What rpm is the convrter?
I run mine locked at full timing and it's a beautiful thing.
No curve needed when it has a 4500 stall.. Idles nice and clean also.
If I was set on an advance, I guess I'd run 20 base and 35 total as a general "hot smallblock chevy" rule of thumb with 64cc heads/23 degree, etc.
I'm thinking about the new 6AL-2 from msd. It has a progmmable timing curve.. I'd like to try pulling a few degrees out on launch to see if it 60fts better. My heavy car really strains against the converter with tall gears and a PG trans.
Goodluck! I never learned which springs/bushings worked well, etc.