Six Pack Pix

The only ref I have is what Mopar Muscle did some years back on the intake shoot out.
The 6-pak was excellent, but probably not worth the expense ever unless you "Want it" over a 4bbl. In theroy, it does have an advantage over a single 4 when running around town, but once you start upping the cam and porting heads, mileage be damned and gone.

The RPM took top honors. But in general, they all did well.