Bill a NE-1 [ 7.60] team ran a 7.64, and wanted to get closer so he ran 4% and ran 7.54.
if you are going to run high % of nitro you would need to run lower compression from just alky, and up the timing.
In 1964 I ran 75° with a bigger pump than the west coast guys were running, on my 301 ci SBC JrFueler, and ran 191 mph, smoking the tires in a high gear car.
I sure miss those days, nitro is fun !
I'd like to get a nitro JrFuel series going out west, all I need is tracks to race and a bunch of cars built.
Have Fun !
Jon