When i start to let the clutch out on my 79 z28 the cluthc will catch then let go then catch and the car will shake alot no matter how high i rev it or how fast i let out the clutch well if i pop it some times it will not shake. so i was wondering could that be the clutch. and i can rev it up and pop the clutch and the rpms wont really go up or down until the car starts to move then they will drop

 

For one thing popping the clutch does the car no good. Your clutch is probably bad, motor or/and tranny mounts may be broken.

 

Your clutch could simply be worn out too.