Pontiac made a turbo Trans Am in the late 70s that was a carbureted 301. It was a limited edition. They were all painted white from the factory. My son bought one a few years ago. The turbo needed rebuilding so the previous owner took it off and put on a regular intake. It ran like crap so he sold it cheap. It was a low compression engine that needed the turbo. We rebuilt the turbo and put it back on and it ran great. He sold it to a neighbor who put it in his garage on blocks and it's still there. We considered putting on the higher compression heads from a non turbo 301 but the guy in California that sold us the rebuild kit said the bottom end wasn't strong enough. Pontiac lowered the compression instead of strengthening the lower end. If you're building your own turbo V8 start with a block that has 4 bolt mains. If Pontiac had done it right their turbo Trans Ams would be more famous than the Buick grand National.