Please excuse this Dummy question. But, I just wanna get this straight in my mind.
In the Class Racer Info guide, I see that for many engines there are a couple of numbers listed for legal factory carbs, and either a 1901 or 1903 Edelbrock Q-jet, depending on whether the engine came with what we call a 750 or an 800 Q-jet. It appears that they are separated by their max allowable venturi size. So, for this post I'll just refer to 'em as a "big" or "small" carb.
So here are my questions:
(1) Have these rules been changed, or relaxed, to allow ANY small carb, for any GM engine that came with a small carb, and ANY big carb for any engine that came with a big carb ? Again, I realize that no carb can have a larger venturi size than what is listed as legal, for the engine.
(2) If the answer to #1 is no, then exactly which replacement Q-jets are legal ?
For example: Can you use a different number carb, from your engine brand, but not from another GM brand ?(such as a side inlet Chevy carb instead of a BOP front inlet carb)
And for the big carb engines, can you use any big E-carb, or just the 1903 ?
http://www.carburetion.com/Rochester.asp