Why is it bad to have a poly transmission mount with stock motor mounts?

 

im wondering the same thing cause i have em and my headers r hittin the body bad

 

this one is easy.........Stock mounts give a lot. The motor and trans is held in by 2 motor mounts on either side of the motor and 1 trans mount on the tail of the trans. Now if all 3 rock back and forth thats not that bad, if the motor mounts are poly then the motor cant rock when rev'd so thats fine, if the motor mounts are rubber and the trans mount is poly then the motor is able to rock and the trans is fighting the rocking motion with the one single mount on its tail, which causes lots of stress on the tranny's case and can cause the case to crack.

 

is there an easy way to access the motor mounts to change em other than having to break ure arm to get to the bolts

 

Its alot easier if you take your headers off. It takes longer but its worth it.

 

the bad thing is the headers r welded to the ypipe and the whole exhaust is welded together ne other tips

 

I am going to do poly motor mounts when I do LT's. I am going to put a stock trans mount back on until then. I have noticed a metal/metal type sound at 70 mph and it might be my driveshaft hitting the d/s loop being the mount may be higher than the stocker.
Thanks for the info guys.