I started at 35° timing. I got best power with 40° timing and left it at 40°. The whole power curve showed an increase at all RPMs with 40° advance. I have a Fluidamper style harmonic balancer and TDC does coincide with the timing marks at 0°.
At low idle timing drops to about 10° BTC. This value was BEFORE the bump in timing. Current idle timing should be around 15° BTC.