the mounts between a car and truck are different you will need mounts that are made for a car .the 67 mounts from the factory had trouble breaking.find thelaterones 69 up that were same but had a t shaped bar sticking through aloop .if they break the engine will not roll over.

I'm pretty sure the 454 will mount to the 350 motor mounts,but the motor is larger and will take up much of the engine compartment.You'll also need a larger or higher capacity radiator.Good luck and happy hot rodding.Sincerely,Handy7rick