I did a search..71GTQ.
I see it likes a lot of boost 28-30+. Alot of threads saying the 70gtq is more fitting to run under 30 psi and still go low tens high nines. The 71 can run the same times just takes more psi.
The 71 uses a billet wheel which is lighter than the 70, and i wouldn't be taking a stock 109 block over 30 psi too much. You would be better off with the 70 as most suggest
The 71 uses a billet wheel which is lighter than the 70, and i wouldn't be taking a stock 109 block over 30 psi too much. You would be better off with the 70 as most suggest
see sig
running 24/23psi (two stages controlled with MSBC-1)
without ported heads id say you dont need more than a 63mm to max out the heads which will just barely get you into the 10s on a good day