Sputter at 5400 RPM
I just put a new Edelbrock 750 cfm on my 64 GTO, 389. The engine is a fresh rebuld. We had the original AFB, but it just didn't run quite right.
NOW is pulls like a beast and idles perfect. Needs a bit more dialing but runs great up to 5400 RPM.
I know Pontiacs are not high reveing engines but why would it sputter and lose power at 5400?
It has the stock top end, ported stock heads, mild cam. New distributer and coil, but orignal style.
I am wondering if either
1. Fuel is not flowing fast enough
2. Spark is not keeping up.
Any suggestions welcomed.