Mike C

Here's a pic of the jeep and the 'vette. One finished, one not. Like the rest of my life...half way done. Oh, and a few of my shop as well. Somewhere I have some new shop photos that came out better. I'll look for them at home.

Since both of your diffs are open, I would seriously look into just swapping the side gears left and right. This will change the circlip groove location to match your half-shafts if I understood the above correctly. It is not too difficult if you take your time. Drive out the roll pin holding the spider shaft. Make some sort of support that you can hold the diff. I use an old axle vertical in the vise, then slide the case on it. Remove the spider pin. Now rotate the case slowly, and with the one side fixed, the spiders should rotate out. They will have a thrust washer behind them, and keep the washer and gear together, same with top to bottom. Once the spiders are out, you should be able to remove the side gears. Swap them L to R (up and down in the vise), then put the side gears and thrust washers 180 degrees to each other and rotate back in the case. Insert spider shaft and re-pin. The Nissan service manual tells you which way to drive the pin out and I believe they use some sort of glue on it as well.

The GM heads from that era just aren't worth much performance wise anymore compared to more modern designs. If they have accessory bolt holes they might be worth spending money on, but not if they don't. The non-accessory hole heads were/are much more common and the inability to use later style accessory brackets bites. If you have to have them vatted, magnafluxed, surfaced, seats installed, guides, a valve job, spring pockets opened up, etc., just save yourself lots of headaches and buy a set of Vortecs. Vortecs are 64cc same as the early heads, and both will require a different intake as you noted. There will be ~1 point compression GAIN going from the 76cc heads to the 64cc. On the cylinder head deck of the passenger side in the very front should be a stamped code of numbers and letters. A two digit letter suffix should ID the original application. http://www.nastyz28.com

Nobody makes a ring gear spacer for the Nissan diff. There is no need to since the 10mm shim (or combinations of thicker shims) with the thin shims can be used to shift the carrier right and left. As far as ring gear stampings, a 4.10 gear should be something like 41:10 (41 ring gear teeth, 10 pinion) the ring gear numbers will shift up or down a few and so will the pinion to change gear ratio. 39:11=3.54 37:11=3.36. All will be shimmed differently to get the ring gear to mesh correctly with the pinion gear. Your halft shaft issue I don't know nothin' about. Ask around for someone else who has done the 4.1 swap into a Z. Once again, it may be best to swap the guts of the two cases or possible just switch side gears l to r in the SX case.

Here are some pics of some of my projects. Just finished the dolly for the convertible body. Differential dolly has a reproduction factory HD rear axle with disc brakes that was available over the counter '67-'68. I like my welders. EDIT: went ahead and added another of my Camaro with the new Drag Radials.

Doh! Meant to reference this post right below... http://www.hybridz.org/phpBB2/viewtopic.php?t=17640 Just about everybody I knew who had a Demon went back to a Holley... Some excellent serious High-perf Holley carbs can be had from Divinci. For 99% of street cars, I think the 4779 is the way to go. If you REALLY need no choke and adjustable air bleeds, the 750hp.

What is the spline on the half shaft stubs? Most likely same as the 240sx viscous, darnit.

What is the point of this swap? The SX MAY be a 12mm in which case your carrier won't work. I am assuming you have damaged the spider and side gears (or someone did)? If so, I would try and swap the guts from your ZX carrier into the SX carrier, then you can use all of the shims etc. that are with the 4.11 already and nothing has changed. You should get the Nissan service manual and read up there. Check out some other online sources for info on setting up ring and pinion. Backlash should be .013-.018 which is REALLY loose compared to other diffs I have done. (If memory serves...) Most likely shims are swapped around to adjust for the varying diameters of pinion gears. As gear ratio gets numerically larger, the pinion gets smaller so the ring gear has to be shifted closer to the centerline of the pinion. You will not want the same combination of carrier shims that the 3.54 uses on the 4.11 gear set. If you do use the complete ZX carrier, use the SX shims. Note, they should be a slight hammer fit in order to preload carrier bearings. ~ .010.

If it were me, I would buy a takeout LT1 and T56 from a '94-'97 Camaro or Firebird.

Take it for what it is... http://home.wi.rr.com/montecarloss/408.html

From GM, all SBC and BBC were internally balanced. Until the arrival of the 400 and 454, both in 1970. In 1986 when GM switched to the one piece rear main seal, they eliminated the counterweight from the back of the crank. This meant that they had to add a counterweight to the flywheel, so all SBC post '85 are MOSTLY internally balanced, save for a counterweighted flywheel. The 400 used a damper that was not zero balanced and so did the 454.

Read here, then go spend money on 4779

In looking at the diameters, you could probably use Dana 60 shims. But because they need to be driven in to keep bearing preload, this could be very difficult stacking some thin shims. The GM diffs aftermarket shims consist of two end plates with thinner shims between them to adjust overall thickness, and the package is nearly twice as thick as the Nissan shims. This can then be driven as a set into the case. (Bearing preload needs to be about .010 or so, so not a whole lot.) Most likely the shims that are in there will be fine, but if not, the Nissan ones are the correct way to do it... Backlash on the R200 was very high compared to domestics I have worked on (working from memory here) something like .013-.018 vs. .003-.008. It may be that if you are a little too loose or too tight, may be able to swap the two thin shims side to side. Looks like the thicker shim is used depending on what gear ratio the housing originally came with. The Nissan service manual shows what are available and how much moving one or the other affects back lash.

If I had the parts, I would try it. Here is a little info I have learned. Remove all of the ring gear bolts. On a piece of plywood or rubber mat, place carrier on end with ring gear teeth facing down. Use a drift in the bolt holes to knock the ring gear loose. Work your way around the outside slowly and easily. When you are ready to install the ring on the LSD plan ahead a little. About an hour before you start, put the carrier in the refrigerator. Go ahead and preheat your oven to ~175 or so. "Cook" the ring gear for about 30 minutes. This way it will drop right on the carrier and you can snug the bolts up with no danger of warping the ring gear mounting face. There is a interference fit between these two parts obviously... You are supposed to replace ring gear bolts everytime, but I have reused them with no problems. Same with pinion nut. I have not had as good of luck with used pinion nuts, on occasion they can work loose, so I would get a new one. The actual installation and backlash of diff is the same for the open carrier and the LSD.

Best info I can give is a Nissan service manual. They have detailed insturctions on how to R&R the diff and the availabiltiy of shims if you do need to adjust backlash. You can check it before you take it apart, then reassemble with new stuff and check it again to see if you are still in spec. You will need some sort of bearing puller to get the bearings switched, and another way to get them on. I use a press and bearing separator to install and remove bearings. The first set I did however, the originals were junk so i actually cut the old ones off and installed new ones with a hammer. Ahh, the good ol' days

Check CAT http://www.catpep.com/ They used to have their price list up, but I couldn't find it last week. For example, they have their SFI certifiedl steel balancer listed for under $100 last month. Great prices, at least they were... Their stuff was in one issue of the Summit catalog last year, then disappeared. Don't know what was up with that, but I've seen mentions other on the 'net or in magazines with buildups using their parts.

I guess I should have specified a few gear ratios as well. My original understanding was that 4 speed cars came to the US, and everyone else had a 5 speed all along. I know that was true in Europe and Japan, maybe Oz is same as US? The manual trans 240's in the US were all equipped with 3.36 R200. The manual trans 260's usually had 3.36. The manual trans 280 and 79 280zx had 3.54 while the 80-83 cars had 3.90, except the 3.54 geared turbo 82-83 cars. 81 turbo could not be had with auto. As you can see, there is nothing wrong with the 3.54 with a manual trans, it just depends on the trans. I have 3.54 in my car with what I think is a late 5 speed. It could use more first gear, but the OD more than makes up for that! I'm really looking forward to both with the T5.

I don't know about road speeds down under, but switching to the ZX 5 speed makes the car LOTS more driveable. You can keep up with traffic with sub 3k rpm engine speeds. Here I borrowed this chart on nissan trans based on US cars(!) from zhome.com: 72/76 two piece case U.S. Non-US F4W71B FS5C71B 1. 3.592 2.906 2. 2.246 1.902 3. 1.415 1.308 4. 1.000 1.000 5 n/a 0.864 RearGear 3.36 3.900 (72 thru 76) 77-79 1980 81-83 Borg Warner T-5 {Turbo Only] 1 3.321 3.062 3.062 3.500 2 2.077 1.858 1.858 2.144 3 1.308 1.308 1.308 1.375 4 1.000 1.000 1.000 1.000 5 0.864 0.773 0.745 0.780 Check out the T5. The best all-around trans IMO. Has the low first gear compareable to the early US 4 speed but almost as much OD as the ZX late 5 speed. The T5 and 3.54 have an overall first gear of 12.39. Compared to the late ZX 5 speed which has a 11.94 using 3.90! The T5 and 3.54 is effectively 2.76 in 5th while the ZX/3.90 combo is 2.9055. Do a little math and figure out what is best for you and what your long term plans for your car will be. I bought a T5 for my car. Even switching to 3.70 LSD will have less effective gear ratio on the highway than the 3.90 and ZX 5 speed. THe US 4 speed and 3.36 geared R180 give a 12.01 1st gear, almost same as the T5. I know you didn't ask specifically about the T5, but IMO, it's the best all around for a driver, at least with the addition of an aftermarket shifter.

zgeezer, An LT1 car or L99? Just curious about the existence of the HD engine driven cooling fan on LT1s. I have heard of this option on some cars with towing packages and on station wagons. Did/does your car have the eninge driven fan? and if so, do you have pics?

Should work fine, but may have a tendency to "lay over" I think I would shorten them another 1/4" on the free side and weld all to another plate.

Check out this post here: http://www.hybridz.org/phpBB2/viewtopic.php?t=17640 The 4779 is the best deal going IMO. Less than a 5 hp difference between the two, which is darn close to the dynos' percentage of repeatability.

Here are some general suggestions. (1k-4k ohms/ft) http://www.inct.net/~autotips/plugwire.htm Here is a link on MSD plug wires, they only have 40-50 (NOT K) ohms/ft! http://www.msdignition.com/1wires.htm I like Taylor Spiro pros the best.

Seat inserts in the aluminum head SHOULD be hardened already, but not a real issue with reasonably light springs that L series use. The N42 is more desireable for its larger valves, but the E88 will be fine. Actually, I think the 2.6L E88 had the larger valves... I have an E88 on my L28 that has had the larger valves installed. This will be a fine No money swap, and if he has a flat top short block, a significant performance improvement even with the smaller valves from the added compression.

It has tons of high dollar parts. If it is in good condition and a good price, seems like a no-brainer. If they don't guarantee it and are asking $15,000 then maybe not such a good deal? Too much depends on the condition of the car and the price is probably why you haven't had lots of responses.

The OEM shifters are just a pivot on a plate. Compared to ANY of the aftermarket shifters, they are a real POS. Changing the shifter gives the trans a completely different feel. Worth every penny IMO.