I was using an HEI w/an MSD box. It has been a while since this combo ,,but IIRC the timing was set to 34 degrees total.
I ran a lot of initial timing w/not much advance,,somewhere about 22-24 degress initial & the rest in the advance.
I owe all this mainly from haveing a 0 to positive deck of .003"
Elevation @ the track was 3000-3500 ft,depending on conditions.
MBHD