Modern Motorsports Ltd

Well I have a hunch my 280ZX flanges are a touch smaller than others as mine were v. tight. Either way, if you're concerned at all it's a small matter to have those two edges welded up a bit BEFORE you drill them (so's not to risk any warp effect on stud axial dirxn). I had mine filled and edges built up prior to drilling just so's I'd never have to wonder, I had a LOT less than an 1/8", ZX's must be smaller. FWIW, IMO I'd drill for larger studs and use PROPER slip on spacers. I have both bolt on and slip on with my setup and much prefer slipon for serviceability and easier change of offset with proper 'shims' behind them.

quote: Originally posted by pparaska: Mike, what's your timing at 1600 rpm? The issue is it's not much probably Pete's nailed this one on the head a few times now. NO vaccuum advance is pretty much for full race only. Yes disconnect the vaccuum to simplify tuning in the adjustable mechanical part to make sure it's not playing any error into your settings. But usually only q in tuning is if you want to run ported or full vac. advance, not vac. yes or no. Same difference as driving any vehicle with zero or like 2 degrees initial compared to say 12 or 14 (L28 or v8), one's a lumpy dog and the other runs like a raped ape. The overdrive trans are getting more common now but raceshops/builders aren't always used to this, they may have thought you had a 4spd or TH350 where you'd be doing 3000rpm and have full mech advance of 36degrees on the highway, instead you may be at 20 degrees, whereas with vacc. you'd be at 30+. Mike, to simply 'prove' this to yourself just dial in another 5 degrees or more of timing BEING VERY careful to not stomp it AT ALL. (you don't want to put high load on it at this higher timing, it's fine at light to low load) Get it slowly warmed up and your highway response at 1600 will start to improve (given standard vac. cans are 10degrees and more, you're halfway to getting to a more 'normal' response). This will help confirm it to you. Dragrace only cars etc don't mind your dizzy as they have NO use for the vacc. advance. It's v. good to fully understand all aspects of timing before going with a fully adjustable/and/or custom setup as all aspects have significant roles and when you deviate from a standard setup it can be hard to know the full impact of your changes. Dr.'s Guide to Optimizing your Ignition is v. good as are many web URL's, none handy at school here. [This message has been edited by Ross C (edited October 17, 2000).]

YESSSSSSSSS:-)) No time to type now so it'll be short but wanted you to have some more feedback:-) Everything Pete says ditto. It'll be very driveable and that auto will really help although I'd be going stock stall as not shortage of torque on that roller setup (v. similar to what I have, but mine's not uncorked yet via air inlet and exhaust). I couldn't use any more stall than the 1800 or so I have now. Lower stall allows you to pull out easier/safer/smoother in poor conditions and give less'creep' at idle somewhat. Higher stall throws you right into a higher rpm/torque power band which IMO we don't need. That is a great roller motor and if rest is done right (air in and out) you'll be right beside the vipers and beating those that can't drive them let alone rocking thru the corners in your lighter car (if you do susp. as well and larger treads, if not still OK for normal use). You will want a rollbar to stiffen car. and yes/yes etc etc to some driving school. You learn v. fast that when you want to go fast you don't stomp it, you (best clint eastwood voice) 'squeeze' it. gotta crash now, but that roller 430 will be v. good:-) any lines on another? a friend in Texas is looking for one... PS feel free to email me privately as I can't always hop in here frequently. Don't let anyone tell you handling will be ruined either, mine's 50/50 and lighter than stock with me in the trigger seat:-)

if someone was seriously looking for a strong T5 I'd look up DARKHORSE trannies or similar in Oregon/WA border area. Seen them in mags etc and known a few with good succes running their T5's.

quote: Originally posted by randy 77zt: ever see a 20bt 3 rotor mazda twin turbo?engine will fit easy in z I haven't seen one but they are quite a pricey unit are they not (OEM to a sedan in europe right?)? The v. odd one has been stuffed into a 3rd gen Rx7. The 2 rotor Rx7 model would be nice in a z if you could avoid a lot of their maintenance/breakdown troubles others have experienced. 2 rotor being a fair bit shorter than a 3 rotor which takes a lot of mods on a 3rd gen Rx7 to stuff in. 2 new motors for this one http://www.slip.net/~ysong/redshift.html if anyone has a good URL on the 3 rotors I'd enjoy reading up on them (even a good 2 rotor writeup would be enjoyed, do they get mpg to match their high hp/litre #'s? (196hp/litre stock)

Ahh, when I had that a susp. shop tried to sell me a $$$ kit with a lot of other crap. ZX rear's increase camber as the car is lowered, whether by worn out springs/excess rear load (long trip with v. heavy load), or lowering of your own accord. You've got the right idea to replace all involved if you do get into it. The shock bushings are not a replaceable item and if worn as you say shock is likely shot and potentially springs as well. If budget allows I'd replace both, you will need a spring compressor to disasseble your current rear strut assembly to carry over your old upper perch as well as installing your new spring on the new strut. Strut in and out is v. simple with only one bolt on bottom and 3 up top. If you want to go further I'd take out the rear control arm and replace the bushings in it as well (not a simple task, best taken to shop for the bushing part IMO). Depending on what type of ride you like will determine the shock/spring combo you want. A great midrange performance combo I ran for 4 yrs was BOGE struts and TRW springs(only $55/pr!, bit of work to find them but worth it IMO) out back, TRW only made rears for us and they're a progressive spring stiffer than stock that handled v. well for me (high speed lapping days etc etc). Boge struts are a great unit for regular/spirited use a step below a stiff more race oriented setup. Don't feel bad, I went thru 2 new tires in a 3000km jobhunting trip with all my tools (back then all my tools could fit in my car:-) in my car after doing a lot of work on the car as it rode that much lower:-((

they look a lot like hockenheims and a few other high enders, got a hunch those might be 3pc

I"m surprised noones commented on the lack of decent gear ratios in that 450/5spd setup for any decent powered (and if you're not decently powered you're not looking for a strong tranny) 350Z (1.0 4th and .89 5th or similar AIR). We need close ratio 5 spds like a hole in the head. You can get a realy good T56 with same dough and have function. I never looked past the ratios and saw no info on other ratios offered.

quote: Originally posted by So Cal Z: Yo, Pete Why are you running around in circles. You don't even have your Z running. I've learned w/ my 68 Camaro always waiting to do it perfect,stronger and faster. Race proven and simple. What's the debate. Why know one has tried too get him on this site is beyond me. Seems like he's been there done that. Now all I need is money too buy scca'S 5 lug conversion kit too fit my 16x8 Centerlines that were originally for my Camaro. So Cal, I guess you don't know Pete:-) Just because somethings been done and works doesn't mean others want to take a new try at it from another angle. Theirs a few of us (working cars or not) that enjoy hashing out various possibilities as that's something we can enjoy. I also wouldn't assume an item (your take on Terry) w/o having been given that answer. MANY of us have communicated with Terry over the years. As far as your camaro wheels I wasn't aware Mike/SCCA had a 5x4-3/4 kit? His 5x4.5 would not bolt up your 'maro centrelines. No 'debate' their either, Z31 front hubs and redrill your rears for a cheap swap to access the world of wheels. PS I'll take a higher priced aluminum piece with 1/2 as many fittings to come loose over a much heavier iron one with 2x's fasteners any day I have a bit of $. 80hp cars work and so do 500hp so we enjoy improving on some known working items;-) I'm babbling again, time to return to my earthquake analysis calc's.

If you haven't done a hybrid swap before JTR still offers v. good info/thoughts on how to approach problems IMO. Want any measurements etc on hoodline etc I have a V8 280ZX. I'd doubt it'd be an issue on a 300 as they seem higher AIR and quite wide/deep near firewall (sbc is not a v. long motor). I'm sure members here could help you thru any hurdles you come up against. Are you planning to do it yourself?

I'm wondering if there is an easier way that doesn't involve welding or any machining past drilling holes in a flat plate. From looking at the drawings of the adapter that I have on my car, it seems that if you were to take a flat plate of high strength steel about 3/8" thick, and drill and tap 4 holes in it to bolt it to the u-joint companion flange, you could clock the position of the 6 holes for the CV joint in such a way that you could have room to drill and tap for bolts to hold the CV joint to the plate as well. What bothers me about the idea is the proximity of the holes to one another, no matter how you lock the bolt circles. The other thing that bothers me is running shear loads through the bolted connections with tapped holes. What do you think? http://members.home.net/pparaska/280ZCVHalfshaftConversion.htm (for others reference to Pete's current setup and hole layout) I can't find the diam. of the 4 holes req'd for the OE stub but in any case here's my thoughts: My v. first thought is to have it made out of high grade aircraft aluminum and just have it tapped for all holes needed. Use a v. high grade bolt and then I won't be AS concerned with shear thru threaded portion (thinking of how to additionally 'pin' that OE stub on top of the 4 bolts). No time to check my 'guide' to see what spec one can get capscrews up to. I'd back analyze it by finding out spec on OE Nissan bolts and then see if you can't get a higher grade bolt with same strength in it's 'threaded' region. I know aluminum isn't normal use for something like this but it can be stronger than many steels if right stuff is chosen (and pricey but hey, how fast do you want to spend). Bolt hole proximities may be a factor, that's on material strength as well as you say. Brake calipers are held on in threaded portion routinely and OE caliper bolts aren't anything xtreme in strength terms (checked it out when I did my upgrade). If it could be done with steel that could be quite economical and maybe not that heavy if centre drilled out etc? I've been meaning to visit a machining friend to get a CNC quote on some items and if you had a drawing I could run it by him as well. AIR you need about 20 items to make it pay ballpark FYI.

Does your carb overhang down in front of the manifold vaccuum outlet? If not you should be able to plumb some brass fittings to snake it down below the fuel bowl overhang? I run a performer 600 and like it FWIW. Prior to buying it I checked around and was surprised but came across several independent 1/4 milers who'd had a hard time dialing a 750 in to work well and switched to the 600 and had no troubles. I know they fed up to 450hp'ish 383's so not worried about feeding my 350. my .02c cd:-) Here's a good looking URL for tuning Holleys (can't find that holley thread) http://www.bob2000.com/carb.htm

Great to hear it's running a lot better for you Mike:-) I've always preferred 185-190 temps, seen discussions on what's optimal but never seen a sound conclusion. anyhow, see if this makes sense: -throttle response and power is better when you're going slow/city speeds and temp's are up -your engine (I'm assuming you have our usual hot air intake on top like 99% of us) is getting hotter/less dense air when your temp's are higher (rad heat coming off is greater as is all convection from block) -I wouldn't be surprised if you're experiencing the differences in A/F ratio/ air changing 50+degrees can make (your underhood/intake air{1% power gain per 10 degrees) and your carb is jetted just right for the hot air but leans out beyond the power band w/ the cooler air once you're moving for a while? -have your plugs always been v. clean? anyone running behind you smelling richness? (doubt it) -just a thought, easy enough to check if one 'stage'/step richer improves 'cool' running you'll know, FWIW I can't make my temp's hit 180 on highway with my rad, with the Stewart water pump they spec a Robert Flaw HiFlo 'stat which has 1/8" bypass holes so pressure doesn't build up too high in the block. THis bypass is enough at highway to keep me closer to 160 if not lower (stock temp guage) FWIW. I'd have to block off some radiator to change that, that'd be a switch eh;^)

I looked at the website and pics weren't too clear. What is the main changes on this hood? it's made of fiberglass and it has a slightly raised centre portion? Is that right? Does the centre portion stay raised at the base of the windshield for a cowl effect? How high above the normal 'seam' does it rise? I'd love to see some pics, I've been thinking of having a similar one made by a local metal craftsman who was interested.

quote: I had a knocking sound in my rear suspension for a while, but I found that it was the gland nut that holds the strut cartridge down. It had come loose. Something to look for, if anyone has a mysterious clunk [/b] Just in case some didn't read slow enough, this happened to me as well and was v. annoying, front strut housing top nut came loose and would make a 'clunk' on most any mild low speed bump, took a lot of checking to find that (had strut boots at the time), great reminder of a rare occurence but nevertheless don't want someone else scratching their head solving the same problem if it can be that simple

quote: Originally posted by Morgan: The pinion flange on the diff.... is it the same as is found on the LSD out of a Z31? Or is it necessary to swap flanges? Will a r180 input flange fit onto a r200 pinion? 280Z/ZX R200 flange is not the same as the Z31 LSD flange, but they can be interchanged on the diff's 'bolt-on' to match the driveshaft flange you need...no ideer on R180 but I'd have to guess no first and 'why' 2nd as I've seen R200 flanges snapped before (due to misuse but still....)

Sounds great Mike to be able to spend for that hp like that come spring,I figured $200 should have it streetable for you now (I learned long ago I'd take a poorly tuned V8Z over most any other car anyday:-) and nail it down at your leisure later on. Naturally if you go EFI may as well only spend that $500+ tuning sticker once and not double it up. Fun thing with the 8's is you can enjoy it at 75% tune and 99% of my weekday driving the other 25% doesn't come into play. (and lately wknds are spent studying, oops, I'm whining again) good luck with whichever route you take, I'm scouting off and on for a break on the edelbrock EFI system as it'll meet my needs quite well unless some used deal hits me on the head

quote: Originally posted by Mikelly: Tom, My setup doesn't have a vaccuum secondary. All my stuff is way tunable, which is why I'm having bunches of trouble. Anyway, I have a BG 750 double pumper with a MSD Billet mechanical distributor. Mike Didn't you mention their were some v. skilled shops in your area? Sounds like it's been a lot of work to this stage and may be worthwhile giving ~$200 to a v. good shop to tune your carb in. I drove my 327 for 3-4 yrs no a 'free' qjet I'd played with for ages that was so-so but never great. Then bought a new carb and kicked myself for having run a 'free' one on top of my $$$$ powerplant and not having spent some money/effort on that end earlier. Always down to the weakest link in the system and I'd sure like to see you enjoying the great ride you've built. Might be athought. From expenditures you tossed around sounded like the $ was their so hate to see it sit for EFI etc. No matter the system they all require setup/dial-in. Mech. secondaries are generally a little more tune in work from what I understand. They don't have a good tuning manual that came with it at all? (not to raise rested troubles BTW)

quote: Originally posted by Mikelly: Yup,I have the lower adjustable control arms already on the front and would like to make some up for the rear, but I'd also use the camber plates on the rear in a pinch if they worked with coilovers! Mike You lucky z owners can do that, on our ZX with STA rear susp. camber plates do nothing:-((

Just FWIW, a v. kewl and trick 'sly' way of getting a nice adjustable front end is having adjustable control arms etc modified. David CArrol of Experimental Engg. does this routinely for 510's and some others, send him cores etc if it's not a comon one. Fully adjustable from underneath with OE look up top. Personally I like top and bottom adjustable for all out maximum track width:-) But spacers are far cheaper IMO to achieve that if within reason.

It's certainly possible, a few issues make it a little more involved than a Z IMO. (mainly less room firewall to crossmember to drop a chevy pan down and level) I have a ZX 'old' writeup at this url http://24.179.154.47/jcaudle/V8index.html it's down right now (I don't know why, it's not mine) but is normally up and workin so check back.. after reading that feel free to ask any q's, JTR is still v. good reading, you don't need the setback plates etc but a lot of good info in their. If I don't respond feel free to email directly as I'm not always in and out of here frequently. Their are a few others with V8 ZX's but they're not very forum active. John Haag is one who's around. My steering setup would be different from yours, I have early manual r&p.

quote: Originally posted by needwaymorespeed: Read an articlle the other night on upgading the z brakes,it mentioned using a master cylinder from a nissan truck because it has a 1 in. bore. Would like the bigger bore versus the 79 280 zx 15/16 -like the idea of having less pedal travel and higher hydraulic pressures. Curtis Curtis, be careful. Their is a point where you lose your modulation/sensitivity control (ie. if range is 1/2" vs. 2" just for example) as the range is so short you can't modulate it properly. My ZX unit operates my large 2 piston PBR aluminum (dual 40 or 44mm pistons, don't recall exactly)calipers and OE rear pistons v. well. I wouldn't want it shorter myself. We'll see what happens after I stuff some larger calipers and 12' rotors out back (hopefully next summer).

quote: Originally posted by needwaymorespeed: Going to be converting to coilovers soon and wondering about strut boots. Should we run them on our cars or not??? Curtis if you can find some to fit I sure would, I couldn't so haven't installed any to date..any I did see the OD was large enough I wasn't comfortable that it wouldn't get caught in my spring eventually

This is going to be long. I just went thru this on DIY_EFI and will post what I felt was some v. good responses I got here. Worth noting is one normally gets v. few responses on diy_efi BUT those you get seem to nail down the facts. Any errors are VERY promptly pointed out by others if/when they occur so I take their info v. seriously. enough babbles....for breathing over 6000rpm and 400hp they feel the BBC TB won't quite make it but two would, that's what his 'impractical' refers to:-) Read on... ________________ Hey Ross there are three TBI hardware approaches that you may want to consider, if you want to feed a 420'ish HP V8 at reasonable [less than 6000 - beyond is quite impractical] RPM's....... 1) My favourite, due to simplicity and reliability..........Use a BBC 2bbl twin 2" blade TBI [say for example a 17091047 assembly - or anything from a post 91 application will get you the better IAC and TPS setup] with a set of good BBC TBI low pressure injectors [say 17112560 - engraved 17084304] and install a bolt-in-place post 94 BBC 26-32psig TBI regulator [17113079]. This will get you roughly 670 CFM @ 3"Hg airflow, and about 250 #/HR of maximum fuel flow. Oh, and you might as well buy a Holley 12-903 [or 12-903HP] gerotor in-tank EFI pump kit [or maybe even a Bosch GFP216 in-tank pump if you don't mind the cost of this rollervane unit], and be sure to run it all through a GM "spin-on" EFI medium duty truck TBI fuel filter assembly [15694406 - the replacement cartridge is 15577756 - good for 400+ #/Hr flow at less than 0.5psig pressure drop - also allows for use of either the Rochester style fuel line fittings or for the use of conventional pipe thread fittings by screwing out the inlet/outlet adapters]. Use any GM TBI dual channel box that you wish, and program away. Additionally this allows you to use either conventional TBI intake manifolds [which you ***really*** will want with TBI fuel , with EGR if required], or you can adapt quite easily to any intake manifold that you may be thinking of. You won't find this info posted anywhere else on the face of this planet, but it works extremely well, and all of the parts can be obtained via the local U-Pull or your friendly GM dealer, at reasonable cost. 2) My second choice........Is a Holley 4bbl TBI assembly [there were not any OE 4bbl GM TBI assemblies produced - but there were some OE marine 4bbl TBI setups [[volvo]] which were based around the now commonly available Holley TBI assemblies]. Holley has a number of TBI offerings, with IAC, up to a max of 900 CFM @ 1.5"Hg airflow and up to 312 #/Hr @ 15psig fuel flow. These 4bbl units work well, and can be controlled by any GM dual channel TBI box, but external injector drivers will be required. The archives are full of guys ***trying*** to run four TBI injectors from just the two OE GM TBI 4/1 injector drivers [in two series banks], but, you ***really*** want to drive each of the Holley TBI injectors via an individual 4/1 amp P&H driver for best/predictable results. 3) I have not personally tried this last approach..........Dual 2bbl TBI's, a couple of my colleagues have tried this with excellent results. About all I can offer in this arena is that they used dual 5.7 litre TBI's, on an old non-EGR "Offy" style dual carb intake manifold, wired the IAC's in parallel, and used a GM dual channel TBI ECM together with external injector drivers. Seemed to work well, based on their feedback. I'd like some driving time behind one of these, as I have a few unresolved misgivings pertaining to mixture distribution and throttle modulation. __________reply to a few q's I had on above____ >Impractical as in just not needed with an appropriate power band setup >below that? Motor will run to 6500 easily. In my setup I don't need it as >shifts up their are unnerving for me:-( Don't like jumping sideways. I meant "impractical" within the context of typical TBI injector firing schedules versus climbing engine RPM. Most dual channel TBI V8 boxes tended to fire the injectors once each per every other distributor REF pulse (also out of phase with each other) to promote more even fuel distribution. As engine RPM's climbed, the time between pulses would shorten, and eventually a firing frequency would be reached where it was no longer practical/reliable to inject. As most of the OE TBI applications were low RPM oriented, pulsewidth headroom was not a huge concern for the OE's. However, even some of the OE TBI packages had an "escape hatch" which would allow you to revert to time based fueling at fixed (say 12.5ms) firing intervals, based on high MAP and RPM thresholds. Still, this only offered a minor extension in headroom over the previous scheme. In your case, with a healthy 6500 capable mill, you might want to consider stepping right on up to port style fuel. As a saw-off I guess you could try using a GM "port" ECM to run a TBI unit. In contrast, the port box will fire both injector channels in unison at either once per every two crankshaft rotations or once per every one crankshaft rotations. You'd have a lot of calibration manipulation to jump into, if you took this approach, and there are mixed reviews/opinions on exactly what effect the reduced port firing frequency has on idle & low RPM TBI fuel performance. >> Oh, and you might as well buy a Holley 12-903 [or 12-903HP] gerotor >in-tank EFI pump kit >Can I use an out of tank pump? My car was EFI OEM so tank/outlet is baffled >etc. Sure! In fact, you can use the Bosch GFP216 (aka 0 580 254 984) mentioned earlier, as an external pump as well. There are a number of suitable external pump models available, from Bosch and others. I like to put the pump in the tank whenever I can, just because it avoids all the suction/lift problems associated with the external setups and it makes things quieter. If using any portion of your vehicle's OE fuel circuitry then keep an eye open for restrictions, especially on the suction side of the pump. >>conventional TBI intake manifolds [which you ***really*** will want with >TBI fuel , with EGR if required] >Now which TBI intake would I want? I've understood (correction welcome as >usual) OE ones won't flow past 5500 tops. Mine has to flow to 6000 or a >hair below. Fairly simple 'adaptor' I assume to bolt your 2bbl TB above to >the intake? Yes, what you've said is correct. With a bit of porting and clean-up the OE 's can be made to flow quite well, but not to the 6500 type limits you're talking of. Even the aftermarket TBI specific manifolds won't typically do that. In your case you'll want an adapter plate between a TBI and a conventional manifold of your choice. If on the other hand you were only spinning to say 5000'ish RPM, then I'd recommend keeping a TBI specific manifold, if the vehicle was to be anything less than a full-on race car. To give you an idea of what's possible I run a heavily ported OE 93 BBC TBI water-jacketed manifold in one of my applications, and have spent a few days abusing it on the engine dyno. Excellent torque and response, pulls hard way past 5000 (with healthy heads and valvetrain below), and all EGT's would happily hover within a 70 F spread of each other at WOT at any RPM. Plugs almost all looked identical. On the street it's quite a handful. Is fed by the 2x2" TBI mentioned earlier as option #1. >2) My second choice........Is a Holley 4bbl TBI assembly [there were not >any OE 4bbl GM TBI assemblies produced >-now I do know of a holley 4D setup that's their 700cfm model barely used >for $325US, seems high for the TB but I guess I'd get >pump/injectors/regulator etc as well and I could drive it with GM ECU if I >wanted?? That might be a good route to try first, if wanting to stick with TBI. These Holley 4bbl's are fairly decent units, and can be easily adapted to most carb manifolds. You can run it with almost any GM box (remember notes above), but make sure that you have an external driver arrangement between the box and the injectors. You want one 4/1 driver per each Holley injector, and you also want to keep the fuel pressure at no more than 15-18psig otherwise the injectors will lock-up. You can use the pumps and filter mentioned earlier. I've also seen the 900 CFM units floating around on E-bay and such places. Just make sure you get one with IAC, and make sure you flow & check the injectors before you use it (hint-hint-hint.). >[i have a hard time getting my mind around 2-2" blades feeding 400hp when I >see same inlet size on prepped 240Z's. Obviously they're not making max use >of that inlet as they're not running twice my rpm to ingest same air.] It's all based on your individual application's breathing requirements. The 2x2" flows 670 @3"Hg pressure drop. You'll have to estimate your peak airflow, and compare that to the setpoint above. A 2x2" would probably be a notable restriction in your case. The Holley above sounds like a better deal, or better still go port. >Now possibly from outside misinformation I have assumed I can't do this >'custom/plug'n'play' setup with multiport? 747 ecu etc is all TBI is it or >can it be used on multport? Costs of ECU and injectors were holding me >back from multiport. I've seen 30pph SVO and bosch/takeoff injectors >regularly on ebay etc for quite cheap ($50 and up) but have been told I >should run 36pph? If a the GM ECU can be cheaply used for TPI as well I'd >love to hear about it as I just realized I'd assumed from outside info this >could not be done and seeing the plethora of info/experience on this list >I'm hoping I might be told otherwise? >Ideally I'd like MPI plumbed on my Vic. Jr. if I can find the system within >my budget. TBI could be fun meantime if MPI is too pricey. It would be quite easy to step up to a roll your own GM port system for about the same cost as TBI, and honestly I think you'd be happier with the finished results in the long run. TBI fueling can be pushed to higher than OE anticipated power levels, but this is usually only done in cases where people either 1)see TBI as an intermediate temporary step before going port, or who 2) "have" to stick with TBI to maintain compliance to state/class laws. _____________________________ first quoted post has some info worth saving/FAQ IMO

Those are for 2.5" OD springs only I"m guessing? Adjustable from the bottom or via a big stud on the top? I've got a set of Moog ones that fit a 280ZX that go from underneath and pop up with a big stud I never did install and are FS.