I'm currently running somewhat of a "custom" turbo off a GN. It's currently installed on my '98 Firebird V-6. The engine has a Stage 3 turbo cam and Stage 3 heads, along with an intercooler and I think this turbo is just too small for my hp goals. The car only put down 240whp at 8lbs. It can push more PSI but I just think it's getting overworked. I bought the setup from a friend so I can't tell you it's exact specs. I'll post a few pictures and if you want more details just ask. I'll accept any reasonable offers, as I'm thinking of upping to a TE60 or a GT6131. Pics can be found here: www-personal.umd.umich.edu/~rlthibau/Pictures.html