I had a 2003 GTP. GTPX crow cams in a manual 5 speed. You need to change the clutch, I used a semi metallic. Valve springs Blue power air box Every lifter seized in my engine twice. A total of 64 lifters! I ran a 4:11 to 1 diff ratio Gas vapour injection ( cost less then my missus Mazda 3 to drive around in). I needed to change the intake manifold to a bpt Motorsport unit coz air flow to the right hand bank was less then the left. I also only ran a rear resonator with twin 3inch exhaust. The car was an animal, it would set car alarms off when idling through Perth, it bunny hoped when in traffic, it would vibrate the windows in my house and the house next to me every morning when I started it lol, it sounded better then an cammed LS1 IMO. I loved the car, but it only made just over 300rwkw. The instant throttle response at 3300rpm and above would make every day worth living day after day. The throttle response was so fast it sometimes felt like the revs would be off the clock before I mashed the accelerator pedal into the carpet. The engine would cruise at 3000rpm at 100kmhr and spent most of its life in a second gear compression lockup heading sideways into corners and second gear with the tachometer needle off the clock heading sideways out of the corner. I loved it and wish I still had it really. It put a smile on every face that was in the car. Checkout http://www.modularmotorsportsracing.com/index_no_mobile_detect.htm As they were great to deal with and they know what engines we are using over here in Aus. I just got my my 410kw g6et back from xft and I think the gt was more fun, I didn't have to wait a split second for the power like I do in the g6et. In defence of the g6et, I have only driven it twice as it is my wife's daily driver, so once I get used to the power delivery I might change my mind. Hope I helped.