Gbauer, Without careful study, as I concluded way back, for a mild build I'd grab either Clifford or Offy, if you can get a swap meet deal on one or the other. As Hank said the hotter the build, and the steeper the gears, favors the Clifford, tall gears and mild build or small inches favor the Offy.
I'm not a turbo guy, maybe Hank or Tom or others can comment but my guess would be that with the turbo, you will have plenty of air to fill that big Clifford so that might even be better.
The only 2bbl carbs I like are if theyre progressive. The biggest progressive available afaik is the Pinto Weber carb, about 200cfm at 1.5" Hg which is marginal even for a stock 250cid. So the next common stop is the 390cfm Holley 4bbl. You can always adapt either 4bbl intake down to a 2bbl if you want to try it but I don't see any reason.
Some of the Falcon Six Ford guys run a 2bbl sideways just because a 4bbl wont FIT, so that's a different reason.
