Timing needs for an engine are dependant on a lot of factors.
A flat top piston with a quench to the combustion chamber can need less than a dome with an open chamber.

I had a 512 CID flat top piston, Indy 440-1 heads, 0.039" head gasket (quench), 13 CR that liked 32 degrees. 34 was no different, and 36 slowed the car slightly, but measurable and repeatable.