* Different engine mounts: The Pontiac 400 has different engine mount locations than the Oldsmobile engines typically found in Cutlass Supremes. New motor mounts will need to be fabricated or custom-made.
* Transmission compatibility: While you *could* potentially adapt various transmissions, finding the right one and making it work requires careful consideration. The bellhousing bolt pattern will be different, and the driveshaft may need modification or replacement.
* Exhaust system: The exhaust system will need to be custom-fabricated to fit the Pontiac 400's exhaust manifolds or headers.
* Steering linkage: The larger size of the Pontiac 400 may interfere with the steering linkage, requiring adjustments or modifications.
* Wiring: The wiring harness for the Pontiac 400 will be different and needs to be adapted to the Cutlass Supreme's electrical system.
* Radiator and cooling system: The Pontiac 400 might require a larger radiator and potentially an upgraded cooling system to prevent overheating.
In short, while it's *possible*, it's a substantial project requiring significant mechanical knowledge, fabrication skills, and potentially custom parts. It's not a weekend project. You'll need welding skills, fabrication tools, and a good understanding of automotive mechanics.
