From what I understand, the newer hollys are pretty good, they say they have fixed all the leaking problems they used to have. that said, I am inclined to use the type / kind of carb that the engines came with. I have a 59 348 with a 2816S Carter WCFB, and it was clocked by the highway patrol at approximately 150 mph+ once upon a time.......... and I have had several vehicles with genuine AFB's and AVS's, all of which are very tuneable. Edelbrock makes them, but they are not the same as the old carbs for some reason.