Originally Posted by tclederman
Jerry & Jon,

What is your opinion of the Holley AA1 ("94", 2100, etc) 2-barrel carburetor used by GMC on the 302 (and used on several other vehicles/engines)?
https://carbkitsource.com/carbs/tech/Holley/2100-index.html

It is two-barrel; and adjustable jets are readily available.

For us regular rubes, can the adjustable jets make it suitable for a GMC 270 or Chevrolet 261?

Tim - NOT my favorite carburetor because of the power (economizer) valve design. This is the carburetor that coined the phrase "leaking down".

And I know you do not fit into the "regular rube" category, but adjustable main jets, while great on a single barrel, add an extra degree of uncertainty on multi-barrel carburetors. Most would be better served using fixed jets, especially on Holleys, where jets are so readily available.

Finally, for racing applications, the AA-1, etc. is fine, especially if this is what the sanctioning body requires. But for street use, I would certainly prefer either a Carter (WCD, or WGD), the Rochester 2G, or a Stromberg WW (definitely a "sleeper" and very obtainable).

Far more important than the carburetor selected would be the choice of manifold. NONE of the carbs mentioned above, are going to work as well going through a 2->1 adapter to a single barrel manifold as the appropriate single barrel. I wouldn't even try it without using a manifold with a two-barrel plenum. Did LOTS of testing with the 2->1 adapters, NONE of it successfully!

Jon.

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