[Dick Boneske]

Sorry, I read '65 Tripower in Singleton's post and got that stuck in my thick head!

The '66 "correct center carb" has venturi diameter at 1.170". The casting number of that float bowl is 7031575. Many, such as the '67/'68 vintage Rochester 2 bbls. have venturi of 1.230". But, there are some that have the same venturi diameter as the end carbs at 1.312" or 1 5/16". I've attached a picture of one of the large ones with another showing the casting number 7009834. I don't know what the largest 2GC's venturi sizes were.

Yes, the Chev carb will work, but you may want to use your old throttle base and airhorn. You've got to be careful with the gasket between the venturi cluster and the airhorn---the later ones have some extra idle passages.