Ironhead

I'm going with the T56 with a .64 ratio 6th gear, which brings top speed (6500 redline) down to 166 or thereabouts with the 4.636 final drive. Otherwise the chart I used gave about the same results as yours. This will be strictly a track-day type car....very little street driving....and my goal was simply to gear it for most flexibility within the speed range I am likely to use on track (roughly 40-140 MPH). My current track car has a 5-speed and a very peaky engine, but with its current gearing I never use 5th gear at all on track, while I would benefit from more gears as it only makes good power from 5000-7500 RPM. While I know an LS3 will have a much wider power band, I am just trying to make use of all the gears and have no need for a OD gear to stuff it into for freeway cruising at 2000 RPM. More good advice on shims...I am ordering an assortment of these https://www.mcmaster.com/#standard-shims/=1a2k2tb in 35mm ID just to stack to figure out the correct pinion height, then see if I can find a "proper" Nissan shim once I know the size I need....although I cannot think of any good reason why I shouldn't just leave the McMaster-Carr shims in there permanently. Thanks again.

Sorry, I didn't word that too clearly. This is the crate engine I am referring to: http://www.chevrolet.com/performance/crate-engines/ls376-525 I was wondering about whether the exhaust manifold it comes with would clear the stock steering shaft, Hoke motor mounts, etc.....or if I would likely need to go with some sort of header. I wasn't asking about the intake manifold.

Sorry if my question/wording/presence here somehow fails to live up to your expectations. Not sure what else to say about that. As far as sharing my solution, all I did was to bribe a hoarder buddy with beer, dig through his leftover shims, and through pure luck found a pinion pre-load shim that will work for me. I didn't think posting that would add much to the forum, frankly. Agreed. I have been pondering the ratio choice also, Jester. It is going behind a T56 on an LS3 powered track car. According to my calculations with the T56 gearing and the tires I will be using the car should redline in 6th at 166 MPH....and 3000 RPM in 6th gear should give me 77 MPH. It definitely is not gearing that will promote relaxed freeway cruising, but that isn't really my goal for the car. I would welcome any experience/input for sure though. I have a 4.375 R/P also...as well as the stock 4.08 that came in the diff. As far as availability, I perused the internet and the shim sizes I needed showed up "NLA" on the big Nissan parts websites. In fact all the pinion pre-load and pinion height shims showed "NLA". It does look like the carrier bearing shims are still available, however. My current challenge is setting up the pinion gear height....as the 4.636 pinion is much smaller (shorter) than the 4.08 that came with the diff. So much shorter in fact, that if the "original" pinion gear height shim from the diff is used, the driveshaft flange will bottom out on the pinion shaft while the bearings are still loose. To sort that out, I'm certain your other shim source suggestions will come in very handy. Thanks much for the input.

I just re-read what I wrote in the first post Zed....and I honestly don't see how I could make it any more clear what I was asking for..... You absolutely need certain shims to set up the bearing tension and ring/pinion interface in a differential. How was that not clear? Since these parts are "NLA"....and since people on this forum (probably thousands) must have confronted this as they worked on Nissan differentials...I just hoped someone here had a workaround. I realize now I was "wrong"....but I must say the request still seems clear to me. Softopz....thank you for the suggestion...that is one of the approaches I am going to use.

Everything is looking great. Do you have any idea if any of the various stock LS engine manifolds tend to work on "Z" conversions? I am looking at using the crate 525 HP LS3, and since I don't really want/need any more power...figured I would just use the stock manifold....if it fits the conversion.

Thanks to all who offered advice...LOL...but nevermind I think I have it figured out.

If it helps you, I used a Recaro Profi SPG XL to test fit into the car....that is the "fat guy" model that is both wider and taller than the standard seat. It fit into my car fine. I moved it as close as possible to the trans tunnel (almost touching) so I would have room for door bars on the other side, and it looks like there will be plenty of room. I have read other people's posts about problems fitting racing seats into first gen Z cars, and I am not sure what they were referring to. Even the SPG XL seems to fit fine in my car.

I am waiting on parts from Japan to finish setting up the differential, so I have gone back to body work. Despite my rosy predictions, I did come across a small patch of rust under the rear corner of the passenger side door. I am certainly not complaining...considering the state of rot of cars that other much braver souls are tackling....but it is what it is and it had to be dealt with. The outer rocker panel had some small pinholes where it had rusted through (that was the only way I found the issue) but after wire brushing the rust off I found the inner panel was only pitted. I treated the area with SEM "Rust Mort", then epoxy primed all the bare metal before patching the outer rocker with new metal. I also found that no matter how I modified them, the stock seat mounts would not allow me to mount seats low enough to fit in the car with a helmet on (I am 6'-3"). So, I wound up removing them and making mounting rails out of 1" .120" wall square tube. I welded M8 plate nuts inside the tubes so I would not have to fiddle about with nuts when bolting in the seats. With the side mounts I am using, this allows the lowest possible mounting of the racing shells....the lowest part of the seat is only 1/4" or so from touching the floor of the car....just enough clearance to allow for a coat of Lizard Skin and bedliner down the road. Being a noob welder, I found it a bit tricky welding the .120" tube to the ultra thin sheet metal on the floor of the car without constantly burning through...but gradually figured it out. With these rails I have approximately 4" clearance between the top of my head and the roof of the car, which should be more than enough to allow adequate helmet clearance. I have also started stitch welding the car structure....a tedious mind-numbing process that I seriously question will bring significant benefits. I know stitch welding is controversial....and I agree with some that it may not help a thing...but since the car is completely stripped I figured it was now or never and decided I would do it. Thanks for looking.

I am currently building an R200V from a 300zx with a lot of changes, including OSG limited slip with Skyline GTR 6-bolt axle stubs and a 4.636 ring/pinion. So far everything is going swimmingly, except that with all the swapped out parts there is no way the original shims are going to work. At a minimum, I am going to need new pinion height shims and new pinion bearing pre-load shims. No sure yet about the side bearing shims. The problem is that all my inquiries into these parts have been returned "no longer available". How are people handling this? Is there a source I am missing? Or is it just a matter of junkyard scrounging and tearing apart a lot of diffs hoping to get lucky? Has anyone used generic machine shims from the general industrial hardware market (McMaster-Carr)? Any advice appreciated. Thanks!

"Life" has sort of taken over lately, and I haven't had a lot of time to work on the "Z". In the intervals I have had, I decided to tackle the differential build rather than get into body work. I picked a R200V differential from an NA 300ZX as the basis for the build, even though I initially thought with an LS3 build I should go R230. The problem with the R230 is that the final drive is much too tall for my intended gearing and tires....redline in 6th gear (T56) would have been somewhere around 220 MPH (yes I know it would not go nearly that fast) and I could not find any available ring and pinions to change it. Knowledgeable people told me that the R200V is quite strong and should handle the V8 swap just fine. It comes stock with a 4.08 final drive, but via Ebay I also bought ring and pinions in 4.375 and 4.636 that were available from some sort of nameless "Japan only" applications. I am in sort of a quandary as to which I should use. The 4.636 would redline in sixth gear at 166 MPH, the 4.375 at 177, and the 4.08 at 189. At 3000 RPM in sixth gear speeds would be 77, 82, and 87 respectively. This is a track car build, that will be street driven primarily to and from track days only, so I am not hugely concerned about highway cruising comfort. I am leaning toward the 4.375 final drive but would hugely appreciate some input from those of you who have done this. My diff casing as received was chipped and rusty. Can't have that can we? So I wire brushed all the crap off, epoxy primed it, and painted it gloss black. I was looking for a proper 2K single stage (no clear coat) paint for drive train components that would be durable and solvent resistant, didn't want to spend $600 for a gallon of Imron, and settled on Delfleet Essential by PPG. It is a reasonably priced product, designed for commercial applications on trucks and buses that will not be clear-coated, and so far seems like it meets my needs well. Easy to spray, good gloss, and dries very hard and (apparently) durable. Thanks for looking.

Looking great... I wish I was even CLOSE to that point with mine...

American Stripping Company in Sacramento. Very happy with the work they did. They took off all the undercoating as well....although I had to remove the seam sealer myself as it is largely resistant to the blasting process. The only problem with having the car blasted, is getting the remaining blasting media out of all the nooks and crannies. I still have a lot of it falling out of the frame rails, etc. Not a major problem, but definitely annoying. The only other alternative is acid dipping, which definitely brings with it some potential issues as well....from what I have read. Also the closest place to me I could find that does acid dipping was in Oregon. After blasting they used Lusid EP210 epoxy primer, which I bought a gallon of also to touch up the various areas after doing bodywork, roll cage, etc. Great stuff....reasonably priced (as auto finishing products go), easy to spray, and super durable. Thanks. Yeah, my current plan is to get the car completed finished and painted, then hit all the blind cavities with the Eastwood product, and go over that with SEM cavity wax. Sort of a "belt and suspenders" approach. Since the car is all stripped and cleaned now, I figure it makes the most sense to apply the rustproofing products after final finishing so there is no chance of them screwing up the adhesion of the paint. Regarding the weld through primers, I have read up about them a lot and most of the reviews have been mediocre. There was a guy on YouTube who actually tested them on pinch welds....then left the parts out in the elements for a while. Next he pried open the welds to see how well the primer protected the metal. There was a lot of rust. I guess the conclusion is that there are no perfect solutions....but I would have to agree that for any kind of lap welds the weld-through primers are about all we have.

Just wondering, what diff and CV axles are you using?

Just working on replacing damaged or otherwise ugly sheet metal. This is the first time I have ever done any sort of bodywork, and I was a bit apprehensive about how it would go....but so far it seems pretty straightforward. I am spraying the back of the "blind" panels with epoxy primer before I weld them in, but obviously the welding will burn off the epoxy in the immediate area. Any suggestions for rust proofing the resulting bare metal on the backside of the panels, since there is no longer any good way to get at it? I was going to spray in one of the "cavity wax" products once painting was complete, or is there a better solution? Thanks for looking.

Great work....I have huge respect for your bringing that shell back...I honestly think I would have run screaming from that one. BTW...I like the larger pictures. The earlier ones in the thread were too small to really see what you were doing.

Car is back from media blasting and has been epoxy primed. No real surprises emerged, except it had a fairly substantial dent right behind the driver's door that had been pulled a bit and heavily bondoed. Also the rear hatch had somehow been damaged...was all rippled....and will either need bondo or replacement when things go back together. The only rust was the small spot (2"X2") under the driver's seat that I mentioned in my last post, where someone probably spilled a beer in 1977 or something. Nice knowing exactly what I have to work with now, and also nice that it no longer smells like foot, ass, and mold. Next up is carefully positioning racing shells and welding in brackets for them, so I know where to start building the roll cage. That should be interesting since I have never bent a tube before. There will also be extensive seam stitch welding and strengthening of the underbody rails with the Bad Dog units. Thanks for looking.

Great to see, and very timely for me. Outstanding work prepping the chassis. I am going along the same route but am far behind you. I was about 80% convinced I was going to use the Hoke kit and I think you just sold me the rest of the way. Branden, not sure what you mean by remote bleeder...? You mean for the clutch slave cylinder?

Project is in total disaster mode. Found rust on the driver's floorboard. Game over. Actually just wasting time. Don't have a real update. On waiting list for car to be media blasted.

Just more boring teardown photos..... Car is completely dismantled, and again I am very happy about the condition of the OEM metal. I will have to check "rust repair as needed" off my list of jobs. It does have bowed up floorpans from improper jacking/lifts, which I hope I can address with a 5# rubber mallet and a section of 2"X4" lumber. Next on my list is removing all the assorted brackets/harness attachment points that I won't be using, and wire brushing off most of the seam sealer in preparation for media blasting. Thanks for looking.

Just a small update....been spending the past week gradually disassembling the car. I realize this forum probably does not need more photos of dismantled Z cars, but for the sake of thread continuity, here they are. Big job, tearing a car down to every last nut and bolt. I have worked on cars a lot before but never a complete disassembly. More time consuming than I expected....and I expected it to be time consuming. So far shell looks good. Frame rails are a bit dented and abused, but still no sign of any rust at all. Thanks for looking.

As the title says....I am just starting the teardown on a '74 260Z that I am going to strip, media blast, cage, and swap in (probably) an LS3 and T56 6-speed. Here are pics of the car in its current form: The car clearly has had some cosmetic restoration work done to it during the course of it's existence, and some have expressed to me that it is "too nice" to do to it what I have in mind. But it really isn't all that nice. The paint job looks OK from 20 feet, but in reality it is a cheap respray with over spray on bumper rubber, glass rubber, and many other places. Also, the engine is just....tired...and it feels like it is putting out about 80 RWHP. And finally, it is an automatic....and I have trouble believing that first gen Zs were even sold with autos....so out of character for the car. In a nutshell, I have no hesitation to strip it down and start over. The plus...I cannot find any rust...anywhere. I think the car spent it's life in the Mojave desert. The plan (subject to evolution) is to make it into a pure track car that is still street legal (barely). I will try to keep regular updates. I have just started dismantling it.