When I swithed from gas/carb to alky/Toilet a few years back I kept the #8NGKs in and left the timing at 38degrees and it ran great, Combo; 500" w/ IndyEZ-1s. Since then I have switched to NGK#9s with no noticable difference and run my timing at 35-36degrees. best of luck with it.
Curtis


Taking over the World one win light at a time.