You'll just want to swap in the block, the intake won't clear.
You should move to mid-6's in th e0-60. You won't get much more hp, because of the restriction in heads and intake, but if you put a 3/4" spacer between teh upper and lower intake your hp should jump to 215-217hp.
the 4.2L makes 202-205 hp, but 255-260 ft/lbs of torque. The Mustang has a more aggressive tune, and you'll neet a programmer of chip to run the combination so with a proper tune, it could go up 7-15 +- more depending on octane, etc. http://www.lotpro.com/cars/2006/ford/f-150/techspecs/ http://www.fordf150.net/specs/engines.php