First and foremost, I am not very mechanically inclined, I am really just learning about motor work etc. As mentioned previously, my grandfather sold me his 1970 goat. Talking with him tonight, he told me the car has the original 400 YS 4bbl in the car (rebuilt around 8 years ago, and driven maybe 200 miles since) He told me the motor has been bored .30 over and has a chevy 454 carb on it right now???? He said he has the original carb but it is leaking.... As a favor, he is having the motor/heads redone again, apparently they are at the machine shop as we speak. With all this said, is this a good mixture with the carb and bore, or does it really matter. Hell, I may even need more info about the carb. Does anyone know what kind of output this setup might have?? Also, is it difficult to rebuild the original carb, or should I let a pro do the work?? Any help is appreciated. P.s. The car is still in Illinois, so I can't provide any additional details right now.