Dougsupra

I am rebuilding my 455 for my Cutlass, does anyone know where to find poly motor and trans mounts? having a hard time finding anything except the crappy rubber ones.

joe_padavano

Rather than hijacking a threat that is only marginally related, here's your very own shiny new thread.

No one makes poly motor mounts for an Olds, period. Rubber or solid are your only options.
The trans mount is the same as other GMs.

Dougsupra

Thanks, I was afraid of that.

ronskal

Energy Suspension makes a polyurethane transmission mount, P/N 3.1108G available at O'Reillys or no doubt online.
I just bought last month US made by ACM main engine mounts (standard rubber-not poly) from Inline Tube.

Dougsupra

thanks for that info. Thinking I may call them and see if they will make a custom set of poly mounts. Shouldn’t be too difficult.

oldcutlass

Just use a solid on the drivers side and a rubber on the passenger. Trans mount doesn't matter, rubber is fine.

brownbomber77

You can drill through the rubber motor mount and stick a grade 8 bolt through it. That'll make it pretty solid. Trans, leave rubber especially with that kind of power. If the engine is moving, even just a little, and the trans is being secured all the way in the back by a nearly solid mount, the transmission case wasn't designed to handle that kind of twisting motion.