Wow that's a little better (.1-.2) ET than I expected....but then i figured your heads were more like 280-ish (like mine) and not 300cfm.
The et is very good for the MPHso the combo is working, I'm wondering if the intake may not be keeping up with the heads at the top of the range which hurts your MPH some, but all the same I wouldn't give up the dual plane's additonal grunt because it seems to be ET'ing on torque.
