Ok I found it easier for me to set the degrees on the light to 34 degrees. Vacuum advance unplugged I revved the engine to 3500 rpm ,actually the balancer mark stopped moving at 2500 rpm but I still took it 3500 rpm. At 3500rpm the balancer mark lined up with the 0 degree mark. Dropped the rpm back to 740-750 rpm and the base was at 12BTDC.
So what I have is 12BTDC base timing, 34BTDC total timing, and 22 degrees mechanical all in by 2500 RPM. Does this sound right for a early 90's goodwrench crate engine (hecho en MX) low compression old style heads in a 84 chevy short bed truck? Thanks