I wonder if, since I hear the change to up the power from '03 to '04 was to switch from 2 valve to 3 valve heads, they can be swapped out?

 

the swap is fairly straight forward, however the throttle body will have to be your 2 valve one and you'll have to work the cams gears so they are not adjustable and you'll have to run the 2 valve computer.

you'll also need the exhaust manifolds and front engine cover at a bare minimum.


check on a couple of the other threads asking this same exact question I posted a link to a saleen mustang getting the swap

 

tj, im lovin that siggy! i have a V6, and i was thinking the same thing. im not going to do it, but it would be cool to have a 3 or 4-valve V6