I currently have a 02 wrx with a pretty modest but nice mod list. My plan is to make 400whp with this 02 wrx and still be able to be reliable and have a fun car, i live in north dakota so i will also be driving in the winter occasionally. My mods are Full turboback exhaust, STI Tmic, ID1000s, DW pump, E85 with Cobb. I have a spt intake and grimmspeed Air oil seperator. My question is that i would like to begin to tear into my motor and was seeing what i should do that will be the most power and also being some what cheap. im looking at 400whp and dont know if i should get cams or should i just get new pistons and valves or what??