I read somewhere in one of these forums about using the 5.4 S/C Ford GT camshafts in the 4.6 03/04 Cobra engines. Did a search and couldn't find anything. The person posting said it would gain hp without the rough idle of aftermarket cam kits and that you could run it with stock springs thereby eliminating any cam kits. I just had a rebuilt engine installed. The rebuilt Ford sells with a 75,000 mile warrenty. So I'm assuming once I do this swap my warrenty is gone. Anyone have the info on the 5.4 to 4.6 cams swap and how much of a benefit would it be to the 4.6?