Chevrolet: vibration upon excelleration, chevy camero, drive shaft


Question
-------------------------hi sorry to bother you again, you say motor mounts, i just also just thought about it and i am not doubting you however i dont think i mentioned the vibration is in the rear end of the car, could this still be motor mounts ? thanks again

Followup To   
Question -
hi
i just bought a 1991 chevy camero z-28, and there
is a vibration when i accelerate, it will stop if
you let up on the gas or if you speed up faster, what could this be, i have been told everthing from u joints to a "trans shutter" and that it is caused because someone has changed the shift pattern to the car for racing, one mechanic has taken the drive shaft off and checked the u joints and says that is not the problem(i'm not sure i trust him) i have had the tires taken off and balanced also(by suggestion of another person), please help with any suggestions you may have of what this problem could be.
thank you for your time
cyndie
Answer -
HI  CYNDIE
  The first Thing that comes to my head is MOTOR MOUNTS
if you put the car into drive and keep your foot on the brake and give it some gas if it starts to clank it is the drivers side motor mount for sure , but it could be the other side or the rear mount also as you do not say that it
does anything to the cars performance right get the motor mounts checked front and rear tranny mount . ok good luck
and if it is a standard shift it could still be the mounts

Answer
Hi
Cyndie - Well if it is in the rear, it could still be motor mounts, you said the u-joints are ok. and the tires are good, did you have all 4 tires done. are you sure that there is nothing loose back there ? but still have the motor mounts looked at. and than let me know ok