OK.
I'm using a 1966 tri power which takes three 500cfm carbs. I know a single four barrel is way more efficient, easier to deal with and it's also more common than a Camaro. I just want something a little more impressive under the hood.
Lets just consider I'm going to run a single 500cfm 2bbl.
This foolish exersise is just an attempt to keep this GMC all GMC, which means keep the motor ALL factory Pontiac parts and get more cubic inches.
The proof will be in the pudding.
(1) A 500 CFM 2-barrel is approximately equal to a 354 CFM 4-barrel, the rating scales are DIFFERENT!
(2) If you want to keep GM parts, and yet be different, remember Pontiac had a factory dual-quad on the Super-Duty cars. You don't need to use the factory SD intake and carbs (expensive!!!); an Offy intake with early Pontiac AFB's will work great, and be much easier to work with than the tripower, especially at your altitude.
Jon.