For the drive train, I have the original auto power glide and a new edlbrock 4bb electronic chock carb. I was going to take the advise and get a th350, but now I think I should start at the exhast manifolds. The right one has a new leak, and it looks like the left one is for a 350. What do you think? Also, what do you think of Thermostatic air cleaners? Its going to get cold here in Seattle. Do you think it will help keep the choke from working so hard? Or will it slow down the air flow too much.