dansvt said:with my motor 24,25psi isn't too much :bore 0,020 ,maley 23cc piston,heads stock,upgrade fuel system(cpr,pump gt40,60's ,bap),predator+mafia, jlt,metco 6,input shaft 26 spline liberty gear,spec stage 3+.The 3,4 is for high boost for my pleasure 700rwhp with 94 octane i'm not better with kenne bell 2.8h ?