GMC used Zenith carbs for a reason, they were better than the Rochester model 'B' built by G.M.
The model 'B' that would be best: '63 - '67 from a 292. There is one that comes up on Portland cl from time to time, has a tag, comes with manifolds. I inquired about it awhile back, would only sell as unit, I didn't want it bad enough pay shipping.
