Actually i just called yesterday and was told by HTT that they dont fit and they dont recommend it because of the back pressure it puts on the turbo... . but on the other hand i thought i remember reading a thread on here a while ago where the HTT super stock 62 turbo would be a gread replacement turbo with the jacobs exhaust brake. And he told me that the 71mm takes forever to spool up. I would love to know a list of turbos that work with the jacobs system. I know it has been done with some turbos