Increased compression.I just got a 3.6kb as well, tuning with lund too... just got tuned on 4” pulley, will be throwing the 3.25 pulley first then 3” pulley, might max outt the id1300s on the 3” pulley i think. Are you running 15% lower? How are you making 30psi of boost? I have cams so i might make less...