Well i put it in the air saturday after work and saw a error on me when i put it on. I forgot the washer just used the lock washer, so i took down the crossmember and put it back on with both washer and lock washer and it make a huge difference. vibration is practially gone, can barely feel it there, and only from about 70 on. Guess the "thump and severe vibration" was having the drive train off by 1/16 of a inch or whatever that washer is, because after putting the washer in it was a big difference. And yeah auto parts stores do not offer the trans mount, had to call Gm, its $92.00 i believe. And supposedly from what i hear people told me to give the poly mount a lil bit of time to "break in", so i'll do that before switching back to stock.

 

i dont know what the difference is but a stock one for my 93 was like 15 bucks.

 

Since you already bought the mount and have it in, drive the car for a little while and see how you like it. I put on a poly mount when I had a 96, and the slight increase in vibes didn't bother me at all. Although, after a ride in the 69, anything would seem like driving in a Caddy!

 

Wow i wish mine was that cheap!! I dont know what the difference would be either, its the same trans aint it???

 

Just an update on my car-

I had some vibration around 50 mph to around 65 mph.

I changed out my U-joints today for some heavy duty ones..and the vibration even with the poly mount is gone.

 

did the ujoints feel like they were bad, like any play when it was on the car. ive been thinking of changing mine but they seem tight and i was going to switch to a heavier driveshaft when bucks come so i put it on the back burner. what ones did you get?

 

There wasnt any side to side motion but they felt really loose, and I had noticed the car was clunking when put into reverse. I ended up going with Brute Force from Advance, they were about 17 dollars each.

 

I have solid motor mounts and a poly trans mount.
There is normal road vibration but no thump. I dont mind the vibration at all.

If people are getting a very noticable difference, there is something wrong. I would say the u-joints are going out on those cars. Or like this one they installed it in correctly.

I thought a stock tranny mount was $9 - $15

 

Craby, u-joints don't have to be sloppy to make noise, actually sometimes it's just the opposite. I've had them before that were tight like normal, but from being dry they had chatter marks on the bearing surface of the cross. The needle bearings ride over the ridges like driving your car over those "wake-up" ridges on the side of the road. When inspecting the joints, you won't really feel it at it's worse until you remove the driveshaft and give the u-joints some good back and forth movement. You'll be able to see and feel the chatter marks once you remove the bearing caps.