The change from the summit racing intake manifold to the EdleBrock RPM Air Gap changed the performance of the carburetor. The engine has a slight rough running acceleration and is prone to backfiring up the carburetor. It isn't too bad when it's warmed up but it's still subtle in roughness acceleration.. It reminds me of when it running before I had it optimally tuned. It was fine before the changeover. The Airgap is a bit talker and where I had a 1" spacer between the carb and the intake manifold, I could no longer use the spacer due to hood clearance. Since I've had it optimally tuned at one time, I thought I'd go for the 750 rather than spend another $600.00 on a tune.Of course, I realize I probably have to spend that anyways on the 750, if I get a good 10 HP out of it, it may be worth it to me. I'd like to see Mid 12's in my quarter mile run if possible but even if I break 13's I'll be happy. Best time so far, is 13.58
