If you want to throw on a set of 4V's, I think you would be better off with the Navi or Mach heads. Which are the same as the 03/04 Cobra obviously. But they're designed to build torque in a N/A form. This is just my opinion of course.
Even 03 Cobra heads are a good N/A head, you'll need the C intake thought. If you are going for all out N/A power, go with C heads or newer. If you are going for boosted power, the B heads will work great.
So you all are sayin I would be retarted to do so? Even though the 5.4 would reuire a higher amount of air & fuel at a lower rpm? Do you think the extra cfm required for a 5.4 would offset the extra flow of a 4.6 at lower rpm? Ideas? Matematical formulas? Somethin? I'm REALLY have tempted to do so.