The number of degrees on the balancer doesn't make any difference.

At what RPM does your engine idle? Maybe you're getting some mechanical advance in at idle.

Put a timing light on the motor and run it up to about 3500 RPM (or to where the advance stops moving) and see what your total advance is. There should be about 20 degrees in the distributor. If you see 45-48 degrees, then you have a true 25-28 initial. If you see less than that, then your distributor is advancing some at idle.

Have you checked true TDC with a piston stop to see if your balancer is accurate? You can pick one up from Summit for less than $10.00, and they should be in every hot-rodders' tool box.