Call up Tom Langdon at www.stoveboltengineco.com . He will talk your leg off, but will have a lot of good advice on the 4 barrel choices. He can also tell you about the Holley-Weber rebuilds he sells, they are a progressive 2 bbl, and can be used on your Offy intake with adapters. Here's what they look like
http://www.myoldtruck.com/gallery/files/2/3/8/Engineleft.jpg

The Rochester one barrel is a poor carb for duals. For some good advice on dual ones, search this forum for posts by carbking. He restores antique carbs.


Fred
52 3600
69 C-10