Best fuel additive for 100LL AV Gas?

[bigblockmark]

I know Mark W. is familiar with AV Gas and an additive. I use Av gas too but no additive. 830 HP on pump gas BBC at 10.5 compression and 35 degree timing. No issues in 3 seasons.

Now I want to build a BBC 496 combo with 12.5-13.0 compression and maybe 38 degrees timing and still use Av Gas and make 750 HP +. Figure I am going to need an octane booster. I have heard that MMT is a good additive, but not sure if it is what I need, what brand additive has the best effect on Av Gas, or how much to use per gallon of fuel. I just got a fresh batch of fuel from the local airport last night. $3.89/gallon. Don't want to go back to $10+/gallon race fuel.

Lets hear it.

[jmarkaudio]

Won't need an octane booster at the compression level, av-gas compares to about a 110 octane race gas alone. Turbo 108+ when an additive is needed.