Captain_Zeros

Yup, 3/4" for an r180, which is three 1/4" steps on the bump stop that was supplied with my mount from TechnoVersions. Pretty easy to do with the bump stop in a vice with a hacksaw. Disclaimer, I forget the nominal height of the bumpstop if you have a different one than I did, I'm pretty sure it's available in at least one thread in this forums. Here's a rusty crusty picture I got of it installed by jamming my phone up into the tunnel when I did mine and a picture of my uncut bump stop before the install (check out the shiny spot on the diff! That's where it was clunking from broken mounts!)

Option 2 for sure. No reason not to especially if you've got the RT in hand already, it's way superior to the OEM design. Rubber is strong in compression and weak in tension so with an RT mount and a stock mount sandwiching the diff then each mount gets to play to it's compressive strengths. Using the RT as a standalone with a hanging mount isn't recommended for a stock engined Z as it changes the angle of the diff a bit to "less than ideal". It's really a modification for V8 swap guys as they need the slightly canted pinion angle to match up with the equally canted new engine in the swap.

When I took mine apart I put a pipe wrench on the strut tube, another pipe wrench on the gland nut, then stood on the first wrench and hit the second wrench with a hammer! New strut inserts ought to come with a new gland nut, so as long as you don't mangle the strut tube too bad there isn't much to fear. Sometimes it takes a few knocks with the old persuader.

No guarantee though, my car had aftermarket replacement cartridges (that looked and rode like they were from the early 80s!) but had the original round gland nuts holding 'em in.

Pulling the high tension coil wire from the center of the distributor cap is not recommended. Pull the positive 12 volt power supply wire from the + terminal on the coil, it'll have the same effect without high voltage trying to hunt its way to ground willy nilly.

If your timing is too advanced or you have your spark plug wires rearranged it'll act like that, a real simple check for that is to pull the low voltage power cable off the coil and see if the engine will crank over quickly with ignition out of the picture. I've got a 280zx electronic distributor on my car and it doesn't have much mechanical advance so I have it pretty advanced at low rpm so everything will be happy up at RPM. It causes a bit of a hard start.

I've never had to opportunity to monkey with suspension with the engine out, but I did bushings and struts with the engine in place and I don't see how having it apart would help any.

If you want to attach an external amp to the stock radio's speaker output you'll need a line level converter. It'd probably sound like crap though, 1970s car audio had... a lot to be desired.

I gotta second what Diseazed just said. The stock style mount isn't fragile by any means in one direction... compression. Rubber is great under compression, but not so hot under tension, if you use the RT mount with a snubber the snubber controls upward movement under compression and the stock mount handles downward movement under compression. It's pretty bulletproof and maintains the stock pinion angle. The only reason to use the GM transmission mount to hang the diff is if you're swapping engines & transmissions radically and need to change the pinion angle to something non-factory. Also, just a note for anybody coming across this thread, if you're going to use the GM transmission mount you CANNOT use an OEM one, you have to use an aftermarket urethane one because.... you guessed it... rubber is wear under tension. The Energy Suspension aftermarket mount has a metal interlock cast into it so even if the rubber tears through you don't start dropping big pieces of car on the road.

my '73s bumper overriders saved my taillights from certain death when I got rear-ended. Bent the rear one up though. Perfect part to have on a daily driver grocery getter Z!

If you've got evidence of leakage, I'd replace 'em! You sound on the right track with both cylinders and the flex line. That flex line looks pretty end of lifespan to me. All those parts are available pretty inexpensively at RockAuto. As far as clutch friction parts, it's not surprisingly at all if it slips with the pedal partially depressed, clutches are designed to slip when you put the pedal down, what you would need to worry about is if it slips under load when you're not touching the clutch, which you shouldn't be touching the clutch unless you're changing gears (I don't wanna accuse anybody of anything, but just make sure we're at square one in case we need to be! Riding the clutch has worn out many a clutch unnecessarily.)

If it has been sitting for over 10 years don't expect it to be drivable by putting new fluids in it. Sitting for a decade is pretty hard on anything in a car that relies on rubber bits.... and there are lots of them. Pretty much everything in the brake system & the fuel system will have to be systematically gone through to make it a driver. My car sat for around a decade before I got it and here is a probably incomplete list of everything it needed to actually be a quasi-reliable car: New front brake calipers New rear brake cylinders All brake flex lines Brake master cylinder Brake vacuum booster Clutch master cylinder Clutch slave cylinder Clutch flex line New gas tank (happened to be cheaper than boiling out the original tank) Replaced gummed up carburetors (I'd expect your fuel injectors to be rather unhappy as well) Fuel filter (Late 240Zs like mine have have two!) Fuel pump. New radiator (original had a hole, not really a common problem) New radiator fan (original fan clutch seized solid on the first longish trip I took on a hot day) New shocks all around, 25 year old units wouldn't clear a speed bump past walking speed. Big ole pile of suspension bushings (honestly optional, but I wouldn't wanna drive a car on 40 year old bushings) including the differential mounts (not optional, they were torn and going to start damaging things) New tires, the old ones turned into plastic time bombs. Various electrical things needed refreshing, including and not limited to the turn signal switch and the headlight/wiper switch stalk and a new battery. Also my car needed a clutch, but sitting PROBABLY wasn't the cause of that. On top of this, this is all on my analog carbureted car, so there are more things in the fuel injection system that might need looking into, but I honestly don't know. Look to the 280Z guys for that, it's not my area of expertise! Anyways, if I look at it strictly as a business prospect, I might have made my car worth more than the cost of the parts I put into it so I technically would come out financially on top if I sold it because labor was the low low price of busting my own knuckles and swearing a lot..... but then I'd be out a Z that I've busted my knuckles on and swore at a lot which I would find fully unacceptable My heavily biased suggestion is if you're going to sell it: don't touch a thing and sell it cheap to somebody who is gonna restore it. :tapemouth

I'm running SUs with the bone stock linkage and I've never experienced any sort of jerk or difficulty in modulating throttle at all. Now I'm real curious what everybody is talking about. :tapemouth

My plastic OEM bushings lasted nowhere near 40 years, they shattered and fell into the transmission to get ground into dust many moons ago. I went with the chrysler door hinge bronze bushings and it was super easy to install and my shift feel is crisp and wonderful. I see no reason to use plastic bushings when such a cheap and easy bronze solution is available. The parts were hanging on the peg at the local parts shop! Around five bucks, just slot in the ones that fit, the rest got thrown in my parts bin.

Throw a tape measure on it. The early booster is 7" diameter and the late booster is 8.5" diameter.

On top of that, a 40 year old rubber hydraulic hose is long overdue to split and spray your precious fluids everywhere. Always replace the flex line when you're replacing cylinders!

The difference between 7" and 8.5" diameter doesn't sound like much, but this is pizza math! A 7" circle has an area of 38.5 square inches, and the 8.5" circle has an area of 57 square inches, nearly 50% more area for air pressure to act upon!

Compression. Fuel. Spark. Your #1 cylinder high tension spark plug wire in good shape? Distributor cap in good shape? Spark plug in good shape?

Two different O'Reilly brick and mortar stores told me they don't stock and couldn't order a booster for my '73 this last weekend....... they could only send mine off to be rebuilt with a 6-8 week turnaround. However, their website had it listed as "in stock" and I ordered one up... it shipped this morning. But that's a late style 8.5" booster for my '73. I heard they interchange fine, but only if you slot the holes in your firewall for the different bolt pattern.

It's a little more complicated than that. It is a fluid coupling that is designed to slip when cold, and then stiffen up when hot, but still allows some slip so it doesn't spin at 7000 RPM and explode when you pin the throttle.

Previous owner set my car up for a GM side post battery, never changed it. No posts on top = no problems!

arg doublepost, damn internets.

Sounds like a Messerschmidt eh? I have limited experience with fan clutch failure, but mine failed in the "on" position and that'd be an apt description of the ruckus coming from under my hood. I'm just making a guess here, but I wouldn't rule out the possibility failing fan clutch going from "slipping too much" to "seized in place" and giving you the problems you described. Try and move the fan by hand with the engine cold and stopped, if it is seized in place like it's bolted to the water pump then it still needs replacing. Alternatively if you had the coolant system drained recently, a bubble in the coolant can give you a world of overheating that suddenly goes away when the bubble burps out.

I've got a dual electric fan out of a late model junkyard altima that I got for like $18 at the local self service yard. Both fans on the low setting will overcool my car on the hottest of days. I don't even have the high speed windings wired up. If originality isn't a concern and you don't mind wiring up electric fans, it's the way to go in my opinion.

Hmm, this is a longshot and maybe a tangent, but the only intermittent ignition I had was on my 240Z when it had the stock points & condenser setup. There is a screw that goes through a plastic insulator that holds the condenser, the points, and the ignition power wire all together and the square nut on the inside of the distributor loosed and eventually FELL OFF, all the wires were still roughly where they were supposed to be, but were making poor contact and intermittently losing contact. I wanted to go straight for the carbs because it felt like it was running on three cylinders, but it was in fact running hit and miss electrically. My symptoms were very similar to yours, I got about two blocks from home and felt like I was running on three cylinders and was able to baby it back home again for inspection and repairs the next morning.