We've had folks tell us about clunks and weirdness and not mention that it idles at 1,500RPM due to some unknown issue. If yours idles at 900+ all the time, I'd definitely know where clunks come from.

Regarding motor mounts, Moog can be good, but I've recently heard folks having quality issues with them. I haven't personally seen this, but heard a few anecdotes. If I took my car to a good shop and they replaced motor mounts, odds are good they'd use whatever Napa gave them and they'd work fine for a long time.

I had specifically checked both cars for excessive power train movement from R to D, etc, and never saw a thing out of the ordinary. I should point out my cars are fully functional and in exceptional condition over all (we don't hesitate to drive them anywhere is any weather), and never though about checking them at a high idle when cold. That might have been more revealing. I'm ashamed I actually didn't check into it further, though I had the '96 apart a year ago (oil pan leak, miserable 3100), and it was fine.
The '92 always had a 'strangeness' on the drivers side, sort of like a tire out of round, intermittently. I only noticed it occasionally on making a turn. I noticed it from the time we bought the car (186K), and initially suspected that it has a rough CV joint or possibly an early wheel bearing issue. I fully expected something to develop, but it never has (now at 246K). Keep in mind the '92 has a 3300 V6, which is a short deck 3800 that is cast for the counter balance shaft like the larger displacement 3800, but they were never installed. They do have roughness that isn't dampened out.
The other thing that I noticed was that the '92 could make the exhaust 'creak' if the car rolled at all in park (I forget if it was forward or back). I could see some movement of the power train that did make me suspicious, and I did look farther and thought the rear mount looked compressed at the time. I did not expect to find them completely failed.

Jerry (CorvairGeek) - What brand mounts did you install in both of your cars and where did you source them from? The el-cheapos listed at RockAuto make me nervous. Awhile back I bought one of those Chinese made Anchor mounts for a TH350 from RockAuto and the mounting holes weren't even close to where they should have been...go figure...so needless to say, I'm reluctant to buy from them again have a repeat of that episode with motor mounts.

Since there appears to be nothing of quality still available in mounts for the old A-bodies ('82-'96), I went ahead and bought the Anchor made ones (and some reboxed for O'Reilly'*). I figured I could at least exchange them locally, under the 'lifetime' warranty. I don't have any active leaks at the this time, and it gives me another good reason to keep them washed under the hood. Keeping them from being soaked with oil (which these had been in the past) may help some.

Thanks. I actually did have good luck with the Anchor F body engine mounts, so maybe I just drew the short straw on that bad trans mount. I guess I'll give the Anchors another shot and hope for the best.

I'm glad to hear that. I'm not convinced there is anything inherently wrong with the ones I've installed, but we'll see. I'm sure keeping oil off of them helps.