Pems with a zzp crossover and down pipe are good for over 500hp and thats the plan for me with the ST2 cam and S256 turbo I have. Ive been emailing stattama a little about this as well. Double roller, 130lb springs ST2 cam 56mm turbo. stock heads stock bottom end, then plan to use either treadstone IC or Frozenboost IC along with at least 65 lb injectors should come damn close to 500hp. Making 400whp is the target.