I bought my gs-t in early 2004 with 94k on the clock. I added a 16g turbo, ported manifolds, 3" down pipe and exhaust (no cat) 550cc injectors, apexi fuel control and boost control. When properly tuned this car would pull away from ZO6 Corvettes from a roll. I loved this car, it has been my 3rd DSM so far and the fastest. All I ever put into it was regular maintenance. The motor never failed to start up, even on cold mornings, and ran smooth alsways despite being raced at the track and on the street. I always had boost set at 17psi and the car never complained!!
4G63 powerplant. Bottom line.
Get rid of the cheap plastic interior parts. And just sell the car with a 16g+ sized turbo from the factory.