Good to know! Thanks, I checked out some scion headers before but looks like that US company didnt end up finishing them for porduction. I would personally like a 4/2/1 setup as squat 4/1 systems are not always the best option, nor do they pull the best figures.. They are however, easier to manufacture. 4/1 Are know for top end wide open power, but lack the pull thru the low/ mid range. With the 2ZR-FE, i dont think you want to loose any more low/mid range and just work on what mid-range we have. 4/1 may be a good option for track use, but im not sure for street everyday use. When i talked to the owner of Advanced headers here in SA, he only recommended 4/2/1, as time after time, 4/1 just didnt cut the mustard. He recommended against a 4/1 system. Do you plan a before and after dyno check on them? Whats the quoted cost inc shipping?