well guys, I just installed my stillen 4-1 header this afternoon w/ no problems. the only thing I do not like about this header (and is not really a bad thing) is that the boltholes fit really tight and you have to put it in perfectly straight, no walking it in like the hotshot, but no problem, the other little thing is the egr tube, but again not that big of a deal, it only took me about 1.5 hrs start to finish on a baking engine. my 2nd gen header was cracked so this thing is ALOT quieter, almost sounds stock. kinda funny b/c when I finally get the nos running those damn cobras are not going to know what hit em' 