I may have come across what seems like a decent price on a 144 roots style blower. I dont know much about these units so ANY AND ALL INPUT IS WELCOME. I know Holly now owns them and since they are older its harder to find parts. But what can I inspect it for other than vane and rotor defects when I go look at it before I buy it????????? Also anything to watch out for or be weary of???????? Not really sure what boost levels I could expect but my block could take about 20 and I know this wont make nearly that much. Are there still different PSI pulleys available???????? Are there any date codes stamped on them or anyway to know age????? What sort of "relative" horsepower gains could one expect. Please share any insight before I buy this bird.