I want to make around 400 hp and would like opinions on engine upgrrades I could do. I am building up just the engine right now, and will drop int oa supra later in the year. What mdos other than the mandatory mhg and studs shoudl I do? Do I really need forged pistons to run a sp61 gt turbo? Is external eg better than internal, and if so, does the sp61gt have that option?