From my memory,???I'm thinking 12* BTDC. w/727
Mind you this is 51 years ago.

When I put headers and cam and a few other mods, I ran 20* initial, no vacuum
advance (old thinking) and 40* total.

The starter had to grunt a bit in hot weather.

Joe

PS As an aside, pure stock, with bumped timing, it ran 13.60s 106 MPH
With the mods, on OE Polyglas, 12.8s at 112 MPH

A lot of fun in those days!!