Travis -
Is your vacuum advance hooked up? If so to which port on the carb? You'll most likely want it to the PORTED vacuum not the manifold vacuum.... ported will have NO vacuum at idle. Manifold will have vacuum at idle.
I'll also ASSume that you timed it at around 12 or 14* INITIAL timing - with NO VAC ADVANCE - that the vac advance was disconnected and the port on the carb was plugged. ALSO if you have a dial back light -- make a map of your timing advance curve. You let the car idle to get the "initial" - then hold another 500 rpms on the engine and check timing - add another 500 rpms and write that down etc. Until you see no more MECHANICAL ADVANCE.... do all of this with the vacuum advance disconnected and plugged. Mapping this will tell us the CURVE in your distributor. You'll need a dial back light to make this easy... as you'll just dial back to zero on the balancer and then read the timing in the light.
Also -- give us the vacuum readings the motor makes. Have you adjusted the idle screws (on the carb) to give you highest vacuum and highest rpms?
