Looking for recommendations on spark plugs and timing.

We just built a 580” BBC for our F/C and need to know what plug to run and where to start the timing.
The engine has 11.5:1, Dart 360 heads, Supermag IV, 14-71 @15# -30# 100% methanol.
Our last engine was a 505” injected BBC so the supercharged 580” is all new to us.

Thanks for the space.

Joe

 

34* should be a safe starting point on the timing, 38* being the max. I run NGK R-5671-10 plug's in my BB Chevy's.