So a guy was selling a v-1 s trim for $2000 he just had it reconditioned from vortech he has the invoice to prove it it cost $750..I know the v-1 is the loud one and its an S-trim he was selling it with and 8-rib pulley which vortech says makes 8 to 10 pounds of boost...Vortech also said that this charger is capable of 20 pounds of boost??.. I know that the v-2 and v-3 are quieter and have self contained oil in the head units but whats the differnce between all the trims???