so i have an 03 5.4L and im wondering if with some mapping and intake and exhaust changes if you can take a set of DOHC 32V heads and slap em on....

 

I just finished a 4.6 DOHC engine swap into my 97 4.6 F150. And I have built a bunch of SOHC and DOHC motors . You need alot more, of which the biggest pita to get is the 5.4 timing cover for DOHC.
If you could get a complete Navi. motor with the exhaust manifolds it would save you alot of headache.

Lowflyingbird

 

awesome! thanx!!

 

navi intake manifolds are a pita to work with....

 

Why is that? I'm considering doing this to my 00 H.D. A set of DOHC heads and a vortec (this won't be for a year or more till I can afford all the stuff) but this site is a fountain of knowledge so whatever info I can get is a plus

 

That intake manifold is massive! If your going forced induction, then get a set of adapter plates to use a 4.6 dohc intake.
Better yet, just drop the Vortec on the SOHC and be done with it! Spend the dough on head studs, new rods, and gaskets.

Lowflyingbird

 

not to mention the long chains on the navi motors tick their but off. and theirs alot of valve clatter on the 4v motors.