Just joined your group today. I'm considering purchasing a 61 BelAir 2dr sedan that started life as a 6cyl and now has a 348 Tri-Power - Automatic. Would like help identifying what else on the car would have been different between the 6 and the 8 and should have been changed. I'm aware of the radiator and fuel line size/routing. I will use code information found on this site to help identify the particular 348. I'm a rodder not a purist so the numbers matching doesn't bother me. Any help will be appreciated.