If the transmission has limited flex from the poly trans mount and the motor can still flex from the stock motor mounts you will break the bellhousing. I would do just the opposite. Change the motor mounts and leave the trans mount stock. The trans should not be moving around anyway. Most true drag cars don't run a trans mount at all but they will have a motor plate and a mid plate. All the trans mount needs to do is keep the tailshaft located.
Last edited by car24 : January 30th, 2008 at 09:24 PM.
In theory maybe , in the real world they don't crack.......
A Dr. from Peoria IL. that has 2 vipers has broke one and asked me to repair it. I told him it would be in his best interest to get a new one and replace all the mounts not just the trans. He replaced the trans mount because he likes to "feel" the trans. Whatever. Anyway in the real world they do break. Not busting chops just stating the facts.
It actually feels a bit quicker out of the hole , less slop,slap,drive train lash or whatever you would call it. It vibrates a bit more , but not enough to make it noticeable or a problem for me. The best part is the shifting under power is smoother , no more torque in the shifter making it harder to shift quickly. I run a B&M Ripper.
Solid motor mounts in a street car seems like it could get annoying if you drive it much. Might want to check with someone that has run that setup on the street if you haven't already.
I use the poly mounts from Woodhouse and they are pretty darn firm. You can gun the motor with the hood up and the engine doesn't move a bit. I know I would not want anything harder as there is already quite a bit of vibration IMHO.