stock are best from the general consensus' around here i believe. at least up until around the ~350-400ish mark i think.
Depends on the header I guess...some of the ones that have been discussed make more hp on stage 2 ish cars then lose it on the bigger turbos. Some of the ones that make it on the big turbos lose it on stage 2...guess you need one suited well for your particular app...:dunno This is my first four banger turbo. I don't have a ton of experience with them enough to really say. All I can say is what I have learned through my own personal research. I am still undecided on a header.
hahahaha don't listen to everyone about the headers. My Maddad ELH did a great job on my car. So well that I got the thumbs up from Siegel when he tuned my car. I gained a redicoulous amount of power in the mid range. Lost NOTHING until after 6500 rpms and that was only 10 hp and I usually shift before that anyways.
i have some prototype Headers/Turbo manifolds coming out in Jan if anyone is interested in testing a set.