Has anyone considered the steamspeed line of turbos? I think the one they make that would be closest matched to that HTA 71 is the Steam STX 71. From what I'm reading, based on others' reviews, it spools early and fast. It doesn't seem to run out of air either in the top end. Someone pulled 452 whp on e85 and found they had an uppipe leak afterwards! Just google Steam STX 71.