Does anyone know if i can get a larger 6 rib pulley for a 03 4.3 GM v-6 ? I had a v-2 s Vortech that my 7.00" x 2.62 was giving me 10 lbs. of boost @ 5800 rpm. I .now have a V-1 si w/ the same pulley combo .& am only getting 8lbs due to a lower gear that the V-1 si has .