Both!
This is on my list to try, and compare to the 4bbl setups in a shootout. Havent done it yet.

I prefer the "B" over the "MV" carbs any day, but I suppose I'd try a set of each to see how much better/faster they were vs each other.

Also depends on the sizes - the "B" carbs come in about 5 different sizes - 3 of the big ones is about like running a 550 Holley 4bbl. 3 of the common (194/230cid) middle size "B" carbs makes about 420cfm at 1.5" Hg, about enough for 200-240hp which should be about what you make with the cam. Depends how much CFM you need.