Naah, think BIGGER...TALLER, as tall as it needed to be to get consistent cross section.

The cool thing about a 180 would be there would be no 5-7 or 2-1 consecutive fire issues the plenum would be about the size of a single plane. it's drawback vs a single plane is it would still want a larger CFM carb and you would still have the more severe dual plane runner angles getting to the valve....and conceivably the runners could enter the plenum from underneath like a short ram.

as far as the original SP2P, I always thought a killer MPG motor could be built around one on a 10:1 273 with late model swirl heads and a modern hydraulic roller cam, it's too small an intake for a wide powerband on a 318 but on a 273 it'd be about the right size....4800rpm peak power with a 318 would be roughly a respectable 5500 with a 273. I could see an A body getting close to 30mpg with an OD 833 and maybe 3.23 or even 2.94 gears.