I am currently running a Y block carb (2100?) with 3 hole base and the stock distributor and it's working great. I picked up a 2g small base and merc manifold at a swap meet last year, but haven't found the need so far to mess with it. Truth be told, the 2g I'm working on today is for my boat, which has a straight keel drive inboard 170 hp big four mercruiser that I can say is still ford related as it uses a single Ford 460 head, 460 pistons and rods. Not a half bad engine.
But back to the subject at hand, I know Tubman and others really like these rochesters, just turn 'em around backwards and bolt on. I guess it's the expensive gm distributor makeover that stalls the plan.