I've tested BB ignition timing many at the track and on multiple race gas and pump gas engines on a engine dyno, all of the ones I tested like between 34 and 36 BTDC total timing for the best ET, MPH and HP and torque on the dyno.
This is with the TDC verified to make sure zero on the timing tab and balancer where accurate, I have found many engines that they where off also
I raced a 1963 415 HP Max Wedge car in NHRA stock for many years, a friend and fellow SS racer had a 1963 Savoy 415 M.W. he raced in Super Stock and swore his motor liked 42 degrees total timing I learned later he didn't build his motors and it had a late model timing cover with a early dampener, which ends up indicating 10 degree more timing than actual
IHTHs