When I was blow through carb, I never changed the jets in 2 years that it was on the car. Even with winter blend it was 72-75% which will be richer than summer blend 85-90%. Too much hassle for no gain. Being a touch rich won’t hurt.


Now I just pump it in from speedway straight into the car, don’t test it and let holley efi closed loop correction do it’s thing. It’ll see maybe 4-5% correction from winter to summer blend.


The amount of knock resistance from e50 to e85 is about the same, only difference will be AFR