[victtor]

HI is it normal for c12 to read richer on my lm-1 wideband over pump gas,im around 12.7-13.1 full throttle ,on c12 its around 12.1 -12.4 full throttle in am running 86 jets in secondary side off my holley im thinking off putting in 84s to lean it up any help or info on this be good first time playing with race full on my 454 bbc thanks
victtor

 

[77 cruiser]

Does your pump gas have ethanol in it?

 

[Tom Mobley]

no surprise, the good gas probably is denser, has a higher specific gravity. more actual fuel in each ounce or gallon. try one jet size, see where you're at.