With the stock manifolds/cam, ther really is no need to go with a 2bbl, the stock single will work just fine. Like the others said, the Rochester B isn't too bad to rebuild. I will admit, I personally don't care for them, seems most of them I've dealt with were either warped or cracked, or both. Couln't even use them for a core. A good alternative would be the Carter YF, model 2100S. Just make 100% sure that you get the Chevy version, as the ford version is jetted way too rich for a Chevrolet.
