I believe the original equipment carb was a Zenith. Not sure of the model number, but we used them on our flathead Ford race engines back in the early 1950's, highly modified to run on an alcohol/peroxide mixture. We outran engines running 3 Stromberg 97's with that one carb.

Carb King can probably get a lot more specific about the OEM carb- - - -I'm pretty sure they're scarce and very expensive now.

Edit: Search Ebay for "2 barrel Zenith Carburetor". There are several carbs listed with those base bolt measurements. None appear to be for a 270 GMC, though.
Jerry


"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
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