Once you get the RPM up above 2500 or so, what happens? You might have over-cammed the engine, and the torque converter won't let it wind up into its power range on acceleration. The initial timing needs to be advanced, but you're going to need to do some modification to the advance curve in the distributor to avoid over-advancing at high speed. When I set up a roundtrack engine distributor, I restrict the centrifugal advance about 7 to 10 degrees, and set the initial timing ahead by the same amount. You will get the best acceleration with about 15 to 18 degrees initial advance, and a total advance, initial and centrifugal, of 36 to 37 degrees. You can add another 5 degrees of vacuum advance for fuel economy, which will drop out almost immediately when the manifold vacuum goes down during full throttle operation.
What is the duration and lift of the cam, and what compression ratio are you running? If the heads are 64CC and you're using flattop pistons, the C/R should be about 10.5:1 or so. That's going to need 93 octane gas, a torque converter with a 2,500 RPM stall speed or above, and a 3.90:1 or lower rear axle ratio.
Jerry
