I am nearing completion of the A15 but before I turn the key I thought I should check to see if the plug gap is the same if I am using a datrats modded bluebird series 2 distributor with a Bosche HEC 715 coil and NGK BP5ES plugs.
I was going to set the gap at .035, but, can I go bigger with the new ignition set up?

depending on how much spark you have you might be able to go up to 0.050" ( i think - what HEI ignitions use in some cases )

basically the biggest gap that the compression doesn't blow the spark out and the ignition can keep up at the high revvs....

turbos sometimes use a smaller gap if they have problems with detonation....

You could probably run .040 easily; I would start there and then experiment with different size gaps until you find what works best for your individual engine and timing( yes each engine is an individual)- . Might as well index them after you find your ideal custom gap. I run .054 with my Jacobson ing sys. It burns clean, I have seen an increase in 8 mpg and I

cheers for the tips! (pardon the pun) I will give it a whirl and see what I come up with, is there a hotter plug I could get away with?
I am running 11.0-1 CR, twin mikuni PHH 40's, and a medium to hot cam