I'm no expert on port size differences between the 248/270/302, so this might be irrelevant without some sort of step down rings....

But here's a GMC 302 - 2 barrel manifold on EBay. Seems like a reasonably fair price, too. (Not mine)

https://www.ebay.com/itm/122015849536

Might open up some different carb options as long as you stay CFM matched.


1951 3100