Powerdyne is not out of business, as a buddy just bought a newly designed impellar from them for my old PD that I sold him. I had a race rebuild done to it by 928motorsports, and with a 7" crank pulley and 2.75 blower pulley on a stock long block it made 12lbs, of boost at 5500 rpms. Before it was rebuilt by 928 the internal belt broke 2x, then I sent it out for the race rebuild and it never failed me again. My buddy now runs the same blower on on his 331 with AFR 165's & E-cam. He is running an 8" crank and 2.75 blower pulley. On that motor he makes 12lbs at 5500, but has belt slip issues with the 6 rib belt. There is another company the he used for his old PD that had good srvice also. Typically it is the internal belt that fails and you can buy the full kevlar belts for 50 bucks online, and change the belt while the blower is still on the motor if your good. The guy with the 331 made like 450rwhp and close to 500 rwtq at Kauffmans Motorsports. This was done pulling the motor no higher than 5500 rpms.