The first time I looked at a perfromer 383, I thought Edelbrock had taken a stock 383 manifold and flipped it 180 degress back to front

The old DP4B was a great manifold for a mildly warm 383; better than a performer but probably not up to the current (much taller) Performer RPM. What I've seen is the aluminum castings back then are inconsistent, some are fine but otheres are soft, esy to strip and the aluminum is 'chalky'. The DP4B I think is more on Par with the Weiand dual plane but both are a step up from the performar 383. On a 4 speed car with 3.91 and up gears I generally prefer the Holley street dominator single plane. It's softer down low but a tad better than even the RPM up top.

Performer < DP4B = Weiand Action < Performer RPM = Holley Street Dominator.