2005-2007 GT engine in a 99-04 body
 

Has anyone thought of doing this or done so already? I know a lot of people are doing 5.4 2v swaps....

yup....search for the member 3v2000gt i believe...he is the first person to put a 3v in our cars

the heads will mount to any ol' 4.6 block from what I gather. The big issue is the motor mount system changed from pre-05 to the 05+ models which makes getting the new block into an old car something of a problem. No worries... use an old block.

From what I've heard, the 3 valve heads flow almost as good as 4v heads yet are cheaper. I'm thinking of doing this or switching to a 5.4

I'm sure if I wasn't so lazy I could look it up, but what parts would it take to facilitate this swap? The 3v heads swap I mean.

how about a 5.4 with 3V heads. That could be made to sing.

If one were to get the 3v 5.4, what all would be needed to do the swap? Would it be the same swap as the 2v 5.4 in addition to maybe the ECU and wiring harness or would the stock one work with a custom dyno tune? I know I wanna go with the 5.4, but now i'm looking at head options, and I know the 4v requires a lot more work.

3valve heads will bolt to a 5.4 for sure. They are modular engines for a reason. And redneck made a valid point the new 05-06 4.6 blocks have a different engine mount system then older cars did. I think puals high performance allready makes adaptors to put older 4.6 motors in the new bodys but not the other way around.

so could i just buy 3v heads and but it on my original 2v engine?

I wonder if you could just drill and tap the block to accept the old mounts since most of the time, the OEMs would just add bosses for the new mounts and leave the bosses for the old style, just not drilled and tapped. I know this can be done w/ Pontiac blocks so I wouldn't be surprised if it's the same here...

3v heads would be fun to tune and intake options become limited, particularly with a 5.4L since no adapter plates exist for it and truck intakes are too tall. Still, it's possible. All things bolt together, just sometimes you need a spacer.

What if you used an intake from an 05-07 Mustang and moved the battery to the trunk so it has a cavity to be used for the filter on the driver side?