Gas mileage 225 Slant 6

Slantsix64 said
16-18 mpg, do a tune up adjust your valves, check your timing.

i get 20-22mpg mixed, but my motor is not stock, 9:5 compression 500avs dual manifolds 4 speed with 2.93 gears, 12 degrees initial 16 mechanical 22Vcan for a 50 total.

Kind of off topic, but what was your strategy to get to 9.5:1? .100” off the deck and head?