If you do not have a boost retard box set the LOCKED timing at 26-28deg to start power tuning.
Max WOT power spark timing will be 26(high boost) to 32deg (low boot) @WOT. on pump gas.
Excessive timing under boost on pump gas will break parts. Sneek up on the tune. Jetting and timing.
For initial start up-warm up idle to get it set up (idle mixture etc) use 36deg BTDC locked timing.
Then reduce for testing under power.