Is this happening under hard full throttle launches or just on around town normal driving. if around town normal driving, I had a 73 that would shudder when you let out the clutch under normal driving conditions..drove me nuts for months..tried a lot of different things....it turned out to be the pressure plate release arms on the pressure plate itself were not adjusted correctly the PP would release unevenly onto the clutch disc causing it to grab only on one corner then slip and shudder. i replaced the presure plate (which was about 3 months old) and it went away.....
I never had any problem launching except from wheel hop...I got rid of the air shocks, added frame conectors, new body mounts and ladder bars then it was just wheel spin from the 427....

 

This is the third clutch in the car since I've owned it and it still does it and yes I did use the clutch alignment tool. One questtion what exaclally is a floating set up? what is the difference between that and ladder bars? The chatter happens all the time unless I really drain the clutch. It gets worse the harder I launch. How much can air shocks affect wheel hop. The only reason I ask is because if I ditch the air shocks then my ride level goes to crap and my mufflers will scrape on any little bump

 

to run ladder bars with leaf springs, you need to "float" the axle on the springs(the axle can't be bolted hard to the springs, it needs to be able to twist ) or else it will bind and effect your launch/instant center

here is a kit at jegs http://www.jegs.com/webapp/wcs/store...13093_-1_10065

 

air shocks at high pressure will hold better than most shocks, at low pressure... well anything can happen, i personally have never had a problem with wheel hop with my air shocks but i run them at or above 100 psi

 

check out the slide a link kit

 

Since you've replaced the clutch disc, pressure plate, throwout bearing, rear springs (New spring bushings and perch pad bushings?), tranny mount, motor mount,etc..

then I'd have to put my money on the frame mount bushings..

I've used ladder bars on 4 2nd gens and traction bars on 2 others..i prefered the ladder bars..I've not used a floater...

 

You might want to look at new flywheels. Maybe yours is allready to thin and the pressure plate does not give the clutch disc enough pressure. Also the clutch disc is not in backwards is it ?

 

back wards clutch disc. never thought about that. have seen it before and it did not show up right away. after the clutch wore down the springs would hit the flywheel bolts when you slowly release the clutch.

still leaning towards the bushings though

 

Ok, My body to frame mounts are shot, I have never replace them does anyone know how easy that is. Will it take a day or a week. The mounts are only 50 bucks so I'll toss em on and let you guys know. I looked at the floating kit and I ned to know if the kit needs to be welded on or is it a bolt on kit? Other than that it all looks reasonably simple.
Also, no the clutch is not put in backwards, I had a buddy do it and when he started his car his clutch would never disengauge!
Thanks for all the help, please keep the info coming

 

Get the kit follow the directions...time depends on the tools/skill you have. but should be able to do it in a day...only do one side at a time...the concept is to jack up one side support the frame on stands and loosen the mount bolts on one side, then raise the body slightly to get some room between the frame and body. then remove the bolts (On the body It threads up into a captive nut. the front fenders mount with through bolts on either side of the radiator) bushings and washers. Clean or replace the bolts and washers...Replace each set one at a time on one side only, then lower the body back to frame, then tighten the replaced side.. then do the other side.
Be sure to torque the bolts to the required specs..

if you have the time, now would also be a good time to clean/paint the mount areas....

use the poly mounts (PST, Energy suspension etc and new bolts are worth the price)

the bolts are usually well rusted and very tight, so a 3/8 socket set isn't gonna do the trick, so at a minimum, a good 1/2 drive socket set and a big breaker bar are usually required..sometimes a cheater as well...air tools will also work well..

the first set i did was on a 71 camaro..I did it in the drive way with a set of jack stands, a bottle jack, some scrape 4x4's, a 1/2 drive socket set and a peice of 2 inch x 3 foot cheater pipe. took me a day...

Greg

 

Ok now all I need to know is what if the captive nut had broken loose from the keeper? is there a way to hold the nut? I don't think this has happened on mine, but if it's possible it may have happened on a couple. It would be good to know.

 

The middle set of captive nuts can be seen by removing the inner fender wheel well rear support. It is located under the blower motor box on the passenger side engine compartment, and under the wire harness pass through on the drivers side engine compartment. however you have to chop a hole in the floor to get to the captive nut on the rear set. they are about even with the front edge of the seat when it is all the way back...

you should not have a problem.. the captive nut and bolt are high quality. I think Gm also used anti-seeze on these as well...

Greg

 

Thanks so much for all the info. As soon as I get the time to put in the new body mounts I'll let you know the differance

Michael

 

Ok I have now replaced the body mounts, which was atask in itself due to the fact that the captive nut had broken loose and was spinning in the floorboard. Anyway, that was the problem, thank you all for your advice it was very helpful.
Now I need your help again; I have an awful shake above 55/60 MPH. I took it to a driveline shop and had the driveline rebalenced, which helped slightly. The tech had an angle calculator and told me my trans was 3.8 degrees down and my pinion yoke was at 0 degrees. I bought some 4 degree shims and just finished installing them. I test drive and the vibration is no better. I will return to the driveline shop and see if I installed the shims properly and that I have 4 degrees up on the pinion. Until then, please let me know what you think.

Michael

 

are the tires balanced? 55 mph vibration is normally a wheel/tire balance issue