I think I would swap the headers first, but I think you will pick up with the 590, I would swap both. 1 3/4 is small for that setup IMO, I'd run 1 7/8 minimum even with the 557.

Make sure you have enough fuel pump, and I assume the glass packs are perforated and not louvered?

Last edited by GTX MATT; 10/16/20 11:19 AM.
Now I need to pin those needles, got to feel that heat
Hear my motor screamin while I'm tearin up the street