Originally Posted by cisco57
I have an 86 gmc truck that originally had a 305motor..I recently dropped a 454 into it expecting the 350tranny to bolt up..everything will bolt up but the torque converter..do i need a new converter or a new flywheel..thanx
I split off your new question posted to an old thread.
Does the converter bolt pattern NOT fit the flywheel on the 454? Does the converter slide up against the flex plate?
Have you checked all six hole in the flex plate and it still will NOT bolt up?
If that is a 'yes'..... you need a dual bolt pattern flywheel for the 454 engine.
The 454 does require a weight on the flex plate.
Also check the back of the 454 crank shaft for a pilot bushing IF the 454 had a manual trans behind in a previous vehicle. A pilot bushing can foul with a torque converter hub that should slide into the crank shaft.