Everything will need to be totally fabricated and custom. But you probably know that. Nothing will "swap". Pontiac engines play very nice with other Pontiacs. that's it. The engine compartment is large and easy to work in. The interior space is quite small. These were not big cars. Anything can be done. Usually when you see these projects they do the opposite of what you are suggesting. They take a modern car and fabricate the older body around it. Much harder with a unibody car.
