The Hot Rod Test of the 383 Intakes - The DP4 versus the Performer (Stock Factory Intake Was Not In That Test)

From what I remember there was like 1 ft lb difference between the two and something like 4-5 hp WOW !!!

And personally I have seen dyno numbers on both intakes and they where within a few hp either way on a mildly built 383 - Apples to Apples

HOT ROD
You'll also see that there's a group of single-planes that are virtually identical (the M1, Street Dominator, and TM6) and some dual-planes that also tested very closely (the Action Plus, DP4B, and Performer). The numbers are so close that you would never know the difference in a car.

The Performer RPM will more clearly outrun the other dual-planes and the differences among the single-planes will become more distinct.