Ok here is the steup i plan i have but not installed yet. Vortech fmu installed 12:1 disk, i have the recalibration disk kit and its says used the 4:1 disk for 40 pound injectors. i have hrc 415cc injectors and s-afc the 415cc are basically 40 pounders. so the question is should i upgrade to the s-fmu or will i perhaps be ok with the fmu while leaning things out if any just a tad with the s-afc? i dont want to have any fuel problems so i didnt know if it would be smarter going with the sfmu.