JMortensen

If you get a cam over about .470 lift you need valve springs to go with it to avoid coil binding the springs. A little more lift and you start running the valve retainer into the seal, so you need seals as well. There are posts regarding these things in the stickies of this forum, read them and you'll know what needs to be done and what seals to use. I ASSumed that he had already changed springs. Not a safe assumption.

I'd get whichever is lightest.

Get a timing light that does advance, set it at the total advance you want with the rpms over 3000 degrees and ignore what it is at idle. If that's not accurate enough, you can disassemble the distributor and look on the shaft near the weights and there is a number stamped on there. Double it and that gives your total mechanical advance. The ZX's come in either 8.5' s or 9's.

Done. It's still a pinion bearing, but pilot is more accurate. You are correct in all of your statements below with regards to which bearing is which and so on. I think the pilot bearing is going to be held in place by the spacer. The spacer sits on the inner race, but if it doesn't go anywhere the outside race isn't going to move either. So I think the lip on your spacer is unnecessary. The spacer itself can only move deeper into the diff, so to combat that I would put the lip on the outside rim of the spacer. Sorry, no cool cad software here but I did some very crappy photoshop editing to show you what I mean. This lip will push the seal out, but I don't think the lip needs to be the that strong because there isn't any force there, you're just trying to keep the spacer from vibrating down into the housing. So I'm thinking if it were really thin, maybe .030" or something than the spacing might not matter. Or I suppose it might be possible to cut the seal down a bit.

90 M30 should have a short nose R200. A short nose R200 won't have a pilot bearing at all. It might have the same tapered roller pinion bearings though.

I just saw your post on classiczcars and then I noticed that you have a "street cam". If you want to run a small cam, the SU's will probably be the better choice. I think the triples will ultimately make more power, but you'll need a bigger cam to take full advantage. That said I'd be inclined to get a bigger cam AND 44's.

Right, but the Intermediate does not, instead it has much larger side bolsters: http://www.racepartsusa.com/shop/customer/product.php?productid=17344 The Roadrace Intermediate is pretty close in design to the Rally Sport, looks like the Kirkey still has a bit more bolster sticking out: Kirkey: http://www.jegs.com/p/Kirkey/760654/10002/-1 Ultra Shield: http://www.vickracing.us/cgi-bin/store/84-62.html

All of the thrust forces are taken by the two large cone/cup bearings. The bearing in question is a pilot bearing.

In my opinion yes. The side bolsters on the Intermediate are HUGE. If you don't want a removable wheel, take a look at the Ultra Shield Rally Sport. I think the lateral support is at least as good as the intermediate because it has shoulder bolsters in addition to side bolsters, but the sides aren't nearly so big.

No, the way I figure it you just a lip on one side. The bearing won't slide because it is pinned between the spacer and the pinion nut. The spacer can't move out, so you'd only need a small lip on the outer edge to prevent it sliding in.

I would think it would be easy enough to leave a lip on the sleeve so that it can't slide deeper into the diff. It won't slide the other way because of the seal.

Yeah, if you have your foot to the floor and the carbs aren't all the way open, then you're not getting full throttle. I used a cable and there is a very tiny window where things can be adjusted so that full throttle is possible. Just a little bit off and it won't go all the way. I don't normally put carb cleaner in the tank, but Techron from Chevron works well, as does the BG carb cleaner, I think its called 44K but it's been years since I've used it.

I caught my wiring harness on fire welding underneath the car. It runs through the rocker panel, so just be aware of it when you're welding near the rockers.

Sure if you want to unshroud the valves there's really no downside to doing so, and cleaning up the chambers should also help with the pinging issue. The N heads have spark plug threads that are cut into the head where the plug itself will NEVER hit. Those should be removed, as well as all the sharp edges in the chamber. Still, if it were my motor, I'd be changing the cam too. If you're going to suffer the ill effects of a bigger cam, you might as well get the benefits too (no pinging). My street cam was similar to a stage IV Schneider and I had no trouble in stop and go traffic and driving around town. It came on at around 3500.

I used one piece of angle iron and hose clamps. Worked great.

Yeah, that ball bearing shouldn't be taking any thrust loads. It just keeps the pinion centered in the housing. I don't know why they chose to use a diff with such a long pinion shaft, I suppose it must have been to tie into the front bushings for the rear control arms, regardless it's less than desireable to do it that way.

I can maybe kinda help with #3. It's been 6 or 7 years, but I think I added about 4-6 cc's to the chamber volume when I unshrouded my valves, but I also cleaned up the chambers, it wasn't just unshrouding. You can use that as a rough calculation to figure your new compression ratio. If you're looking for general advice, I'd say get a larger cam. Since you have programmable EFI you should be able to make a larger cam work for you, and I would guess that it would allow you to run the advance you want without any of the port/chamber work. If you want to do the other stuff on top of the cam great, but the cam is the fastest, easiest, and best way to get where you want to go in my opinion.

The pinion depth and preload are set with shims that are further down on the shaft. You wouldn't screw anything up by pulling the bearing and putting everything back together. The only other thing in there is a big spacer, but if it were to come out you could just stick it right back in and it wouldn't affect any tolerances. I would think you wouldn't want to use aluminum for the spacer because it expands and contracts at a different rate than the cast iron diff housing would. Whether steel would work, I don't know. I'm not a big fan of diff coolers, I think they're mostly overkill for your average Z owner, but bjhines had a pretty good idea with his cooler that might solve that bearing issue. He had the pump dump the cool oil into the passage that leads to that bearing. I think the problem is it's so far away from the sump and if you're going uphill there isn't likely to be very much oil getting to it.

That was my very first car. 79 2.3 Mustang with 4 speed. I called it the Mousestang. It was smurf blue on smurf blue with wood veneer. What a pile of crap that thing was. With my prior experience, I'd pass...

I've had that problem on a road course. Tom Holt posted a really easy fix on classiczcars.com a while back: http://www.classiczcars.com/forums/showthread.php?t=18948 If the choice is SU's or 44 Mikunis, I'd go 44 Mikunis. Don't bother with 40s.

The spacer is an interesting idea. If you wanted to all you'd have to do is pull the pinion nut and pull the seal and that bearing is right there. If you didn't care about trying to save it I'd imagine some creative slide hammering would get it out.

I expect that the HANS would require more room behind your head.

The "sandy" feeling is almost always the front pinion bearing in my experience, which is the NLA one. Supposedly you can't get the Power Brute anymore, if that's what you meant by "PG". If you meant Phantom Grip, well... you'll find out why not soon enough.

When you order a Kirkey you give them 5 or 6 measurements and they build it to fit you. Another option for a seat back brace would be the LR rear strut tower.