Your way safer using 34 degrees BTDC total timing on race gas is what I have learn doing max tuning in the 1/4 mile on ET or MPH
if the race gas is more than 30 days old after opening the can use it in some other vehicle with less compression, all gasoline starts losing octane when expose to our atmosphere, all of them
E85 and straight methanol don't devil scope: : up:
They are both way safer to use when racing also: up:
Without knowing the compression ratio and quality of the gas being used it is impossible to give you the correct heat range to use, sorry
If those #10 NGK stay clean and don't foul out at light part throttle driving use them: up:: two cents:
If they do get real black and ugly looking, try a NGK #7 or #8 next The # 8 would be safer than the #7 but both may work better on the street than the #10 NGK