273 exhaust manifolds

with a 4 bbl you dirve on your primaries which are smaller and more effeicent and when you romp on it you open the secondaries with a 2bbl you are always running on your secondaries so to say.. i could be a little bit wrong but you get the hint..

and with a 4bbl hidden under a air cleaner whos to know, plus like cuda said.. more HP so you win win win..
fuel effeincy
power.

thats your best bet.