Jolane

Thank you for all the replies! Each one is very helpful! These definitely give me something to compare to now. One more question...maybe I am misunderstanding roll center. I know that the tire travels along its path through suspension travel based on the suspension linkage. From the linkage, I can find the instantaneous virtual pivot point. From this I can connect that point to the center of the tire, and the point where that vector crosses the vehicle centerline is the roll center. In real terms though, is the roll center the point at which the vehicle body rolls at that instantaneous moment? If so, why is it desired that it is so far down? Is the roll center height and the size of the sway bar proportional? Thanks again for all the help and insight! Joshua

In general, is a higher or lower roll center preferred? I know that the LCA pivot change is a change to alleviate bump steer, but I have also seen comments on it changing the roll center. If a car is lowered 1", the roll center changes (in part) due to the relationship of the LCA pivots. It lowers the roll center. To me, it seems like the roll center should be as high as possible, but how high is good enough? Should it be at the vertical CG of the car? Thanks, Joshua Any recommendations on where to find good starting points for tuning suspension is greatly appreciated. I have found a lot of info on how to calculate the parameters (scrub radius, roll center, etc), but don't know what a good target for these variables are.

Dan, I think that the choice comes down to available parts. I think the consensus is that the longer the rod, the better (better rod/stroke ratio, reduced piston side load, etc). For my 383, I used a SCAT 9000 crank designed for 6" rods. Same with the pistons, designed for 6" rods. Naturally, I used 6" rods. If you can get the right parts, I would vote 6" rods also for you. As for the LT1, I don't know what is available though. Sorry if this doesn't help... Joshua

While I was at the race shop yesterday I started looking at their cars more closely. These are late model modifieds mostly racing oval tracks (dirt and asphalt here). I was suprised to see how they did the suspension and steering (that is why I was there, buying QA1 rod ends for my LCA's). The lower A-arm looks like it is off a 280ZX, with a T/C rod running from the front instead of the back. Looking more at the steering though, I started thinking about trying to adapt one of the rack and pinions they use to my 240. They are using a Sweet Manufacturing box, but other companies make very similar models. They all seem to mount with a large base plate and three bolts (very simple). I can get a manual R&P to start, and if I desire power later, it is a simple upgrade of actuator, servo, and pump. So, I would kind of like to know other's opinions on whether this seems like a good modification: Build a new crossmember from scratch. Weld it to the frame rails (why does it need to be removable anyways?). I could then fashion the crossmember such that the engine mounting (which I would redo now) would be correct for the SBC I am using. The stock crossmember is curved to the front, I am thinking of either making a straight one, or curving it to the rear (whichever would work better). Since these R&P are shorter, I could lengthen the LCA to match the longer steering rods. This leaves the T/C rod. I figure I could either leave it where it is (making the lower triangle pivot around a skewed axis to the chassis) or move it and use a rod end for the mount. I am thinking along the lines of mounting the T/C rod pivot on the front, up by the radiator support. I could add some reinforcement to the bottom of the rad support. The benefit would be that I can not cut out the original T/C rod mount giving me more clearance for headers. The possible interferences are with the T/C rod and the sway bar, but I now that the 280ZX's made it fit. There is plenty of room up front for this otherwise. By using a shorter R&P, I can move the LCA and T/C pivots inboard some, also allowing for more tire clearance (wider tires) with the T/C rod. Everything would be adjustable now, and quite possibly, much cleaner. I am not sure though if I can make the car handle any better with these changes. If anything, I will reduce the camber change with suspension travel by lengthing the LCA. Is this bad? I either need a good replacement rack or to rebuild the one I have if I stay with the stock crossmember. Does anyone know how hard it is to rebuild a stock rack? If I am building a new crossmember, I would prefer to find a R&P that is easier to mount than the stock one. Does anyone know if a Pinto or Mustang II rack would work with the stock LCA's? I can't find the length from pivot to pivot. I realize this is probably rambling, but I appreciate any and all comments, suggestions, etc. This would be a major departure from the stock suspension. I don't think though that it would be very difficult or expensive. Probably just replace the complete frame rails from the firewall forward, fabricate the crossmember, be done. Heck, why not just use a one piece wishbone lower control arm then, and do away with the T/C rod? Thanks, Joshua

A little off topic, but do you mean rear strut tube assemblies? If so, what kind of cost was it to have them both powdercoated? Thanks, Joshua

Matt, In response to your question about tieing into the T/C rod mount area, I think that is a good idea. I plan to tie the end of my rocker box into this area on my car. Looking at the load path in the chassis, the engine and front suspension loads (from the LCA, not the spring) go into the lower frame rails, which really don't connect well to the rocker boxes or upper spring mounts. They only connect through the radiator core support, inner fender well, firewall, and floorpans/seat mount brackets. No wonder why the front of these cars are so flexible. I feel that connecting the rocker boxes to the frame rails and subframe connectors can offer a lot in stiffness and rigidity. Maybe I am off base, but is seems like the two frames need to connect better that through 'flat' sheet metal. I will be tieing my rocker boxes into the subframe connectors in both the front and back. I plan to also box in some of the frame up front to help in flexing (hard to explain without pictures). I say tie everything in that you can though... Joshua

BlueovalZ, I am ready to order some seats for my 72. I went through the same thing, and even brought home a Jeep seat to check fitment. I was able to measure and compare the dimensions to those of aftermarket seats. I am going with the Corbeau CR1's. I know that some people have the A4's which I guess fit well. The big difference is the seat cushion thickness. The CR1's are a lot taller, making headroom less if using the stock seat mounting corssmembers. I will be making my own crossmember mounts, so I will lower mine to get the seat height correct. This is an important aspect that is not readily appearant. Good Luck on the quest...not an easy nor cheap one! Joshua

The Canton Road Race oil pans seem to be popular. There is a 6 quart pan + 1 quart filter available that is 7" deep (about the shallowest I have seen). It has trap door baffling, windage tray, etc. The pickup must be ordered separately. They carry the pickup for both regular and HV oil pumps. I have a Mellings 55HV in my engine. They are not cheap pans at ~$275-$325 + pickup. I found the cheapest price on Ebay. I don't know what headers you are using, but you should check before ordering the pan. It has kickouts on both sides, making the space tight. Joshua

That is the same system I will be running. I bought the complete system with wideband O2. I hope to have it installed within 6 months (still have to finish fab, paint, then get the engine running. It looks and feels like a quality piece. Grumpyvette, Is that the same stealth ram intake you have been running, or are you using the older model? The new model has injectors that do not protrude into the runner, unlike the older version. Joshua

Whoa... MSA's rear valance pach panel is perfectly flat? I know it is expensive, but it was my backup plan if my transplant from a J/Y car did work well. If it is flat, I have no backup. I would appreciate any information about that patch panel. Thanks, Joshua

Thanks for all the help! While mine is not crunchy hard, I could not get it pried back well enough using three pry bars and a big screwdriver. If I have to cut it, does anyone know who a new replacement is available from, and approx $. Thanks, Joshua

This is a great question that I am very interested in. I fought with mine for ~20 minutes before giving up. I also think it needs to go out the bottom. Can't wait for an answer on this. Joshua

That's uglier than the car they cut up on Monster Garage this week (I think it is called a Zimmer). Ugh! Joshua

Michael, I am not trying to be smart or anything, but did you look in the box of ARP fasteners? I have found the torque specs in the box of bolts before, along with what lubricant to use. On another set of bolts, nothing. Just a thought, Joshua

Pete, It is hard for me to really tell, but I would say that it looks pretty close. Maybe I am just seeing things. The price is definitely not too close though. Personally, I feel that modifying my Lakewood is the best route for me. I can get it as close as possible, and do the bottom and two lower sides. Tuck it up real nice. I am thinking of doing it like a lot of 4x4 guys do their rear 14 bolt axles. Joshua

Although I have never used Desktop Dyno, this sounds like a great idea! I have been meaning to buy a copy, maybe before I build my next engine. Joshua

If you are using the Z31 Turbo axles, you should not have to remove the metal bands on the boot. You can just turn the axle up on end, and tap the CV housing against the end of the axles . It doesn't take much to force the metal cover out. From there you can remove the cage and flip it around. On the Z31 axles, you remove the cage with the balls and center section (the one that has the splines) as a unit, and flip the whole thing over. You may have to use a puller or tap on the center section with a hammer and brass drift to get it off the axle. There is a C-Clip that retains it. Upon reassembly, just make sure the C-Clip is completely seated so you don't shear it off. That is the trickiest part. Good Luck, Joshua I know Ross has some instructions that someone wrote (probably in collaboration with him). I cannot find a copy though that he sent me a few months ago.

Pete, I went and looked in the AFCO catalog. There are two different 153 tooth only bellhousings, and one looks just like that Tilton piece, except it is black and made by Hays. http://go.mrgasket.com/ProductDetails.aspx?brandId=0&productID=21381&majID=150&minID=&selection=3&minselection= For some reason it says that it fits 58-81 engines...why not later? Probably will. The other aluminum version I was thinking of is made by Quarter Master. It does say that it will work wth a 10.5" clutch. For some reason, neither of these are on the AFCO website though. Joshua EDIT: The Hays is $220 from Summit Racing. The summit part number is HAY-77-150.

I will be working on using a 300ZX rear hatch mechanism to replace my hatch latch. I will mount the mechanism on the car, and only the wire loop on the hatch. I am planning on boxing in the region above the license plate to make room for this. I will also source late model license plate lights to mount in this boxed region, and eliminate the stock license lights. I am keeping the stock tail lights, and am a little unsure on what to do with the three piece rear cover. I want to keep the outer pieces though at least. This should net me a cable actuated rear hatch only, no push button. It should clean up the rear more also, as I don't really care for that little push button. These are my plans. I may have to find a smaller mechanism, but from the initial look, it looks like it should fit. I am not sure if you want to do any grinding, cutting welding etc...since mine is stripped, now is the time to do what I want. Joshua

How about wrapping a garbage bag around the lower part of the tranny before dropping the valve body. That way, if any fall out, they will go into the bag? Joshua

Pete, I wish I had known about that before I bought my Lakewood! Great find! I will end up shaving my much larger Lakewood down on the bottom and sides for the "extra" clearance. Although it will no longer be SFI approved, I saw no mention of the Tilton being SFI approved anyways. I also came across a much smaller bellhousing in my AFCO catalog. I can't find it now though on their website. It may have been aluminum...I can't remember now. Anyways, it appeared to be very small but still accept a standard starter and 153 Tooth flywheel, similar to the aluminum Lakewood unit. I like the idea of steel though. Joshua

I will add that although the bearing set from Ross may seem expensive, the complete set was cheaper than my local autoparts store on exactly the same components (brand and model number). I can recommend Ross highly, he is a great guy to do business with! Joshua

First, I think your project is great. I feel that I can appreciate the work involved with this. I also think that bolting the head together is a good idea for a prototype. I would not put epoxy over the bolt heads though for a number of reasons, the biggest being that it shouldn't be necessary. Another avenue you may want to consider is soldering/brazing, similar to what they do with radiator cores. You could probably bolt it together with a fixture, and bake the whole assembly in a furnace to braze the pieces together. If it was my project, I would be inclined to call a custom radiator shop (Ron Davis to start, then BeCool) and ask about the process. I don't know if they make their own cores or not, but maybe they could give you a contact for a core shop. Please keep the updates coming! Joshua

Wagz, How did you assemble the bearings onto your stubs? Did you press them on before inserting into the strut housing, or can you pull them together using the stub axle nut? I just got the bearing set, billet stubs and billet companions from MM last week. Thanks, Joshua

Those are the ones I remember! They definitely look great. Do I need gauges like those? No. Do I want gauges like those? Absolutely! Thanks, Joshua