I like that little lip you leave at the upper/lower plenum transition.

I don’t know if it helps or not, but I like the idea of it.

13106259-FCB0-4D31-BE29-05AED47312FF.jpeg

68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads