Are 454 after market flex plates just a little larger than original flex plates? Starter gear is ingaged and stuck tight, but the solinoid is not on yet, we were just fighting to see. We think we might need some shims, but are after market flex plates the same as originals.

stano,
They should be the same but .... I have seen some of the cheap ones that are really bad as far as runout goes. YOu really see it when you have them bolted to a crank on the balancer. Try turning it a half turn and see if the gear will go in and out. If so, the flywheel has way too much runout and should be changed.

thank for your help BillK