head swap
 

what needs to be done to put a set of 06 heads on an 03 engine?

Going to 06 heads is a tough call, it depends on when they were made because there was a change made in 06 year. do you allreaqdy have the heads? if so measure the dowl holes to see what they measure, they will either be 18mm or 20mm. If they are 20mm then you will also need all the hardware for that head, injector hold downs, and I believe even the rockers because they are different. the dowl holes will be on the face of the head where the head bolts go through on the 2 top outside boltholes.

Yep, need to see if they're 18mm or 20mm first.

is there something special about 06' heads?

No, it is just that as of Jan 06 they started makind them with 20mm dowls and also changed the injector hold downs so they won't work on the 03 to early 06 heads, Not too sure about the rockers but I will look into that.

I have read a few places that you need the corresponding rocker boxes too, but I don't think you do, you just use a different amount of bolts to attach them, depending on year. Injector hold downs are definitley different, the later larger hold downs wont fit on the early heads. T-40 vs T-45 torx.

While I'm not 100% sure where the dowels are, the only thing that comes to mind are the alignment dowels when putting heads on one of my gasser motors. If that is the case, AND you're studding the block, I don't know that a 2mm larger hole in the head on an alignment dowel is going to be that big of a deal. Forgive me if these are not the the dowels you are referring to, but I think they are.

Next, 03 and 06 DO oil the injectors differently, however, if you have the 03 heads there as a donor, you could cannibalize the oiling parts from the 03 to the 06. If you can put an 05 and up HPOP into an 03 block which REQUIRES changing the oiling into the injectors (among a whole aundry list of things that MUST also be changed), then you can go the other way with 03 oiling on an 06 head.

I've heard it over and over, from 03-07, these motors didn't change that much, so if you're willing to do some parts swapping, I don't see why it couldn't be done.

These motors changed quite a bit actually. There's not much that's the same, but fortunately most parts can be swapped.

Things that are different that come to mind quick: pistons, injectors, glow plugs (using the wrong glow plug could result in glow plug to piston contact) heads, rocker boxes, oil feed systems, HPOP's, intake manifolds, turbos, turbo pedistals, FICM's, FICM mounts, ICP sensors and locations, and I'm sure other things.

As for the alignment dowels, it's a matter of what block/heads you have. There are 18mm blocks and 20mm blocks, and there are also 18mm heads and 20mm heads. The alignment dowels do not have a stud passing through them, and yes 2mm would make a difference in how the head sits on the block. Luckily every new headgasket set from Ford comes with the stepped dowels from 18mm to 20mm as well as the normal dowels so you can make it work either way, just need the corresponding gaskets.

Correction, there is a stud that goes through the Dowle, these heads will walk all over the place if you forget the dowls, ARP recommends not even using the small rocker to head bolts as they can pull some tention away from the studs so it doesn't matter what rocker boxes you use on which head. I installed the slamm bolts anyway but I used blue locktite on them and only torqued to 10ftlbs, not the 28 that was called for. Injector hold downs and glow plugs would be the major concern for compatability. You can swap the high presure oiling systems but you have to use every component of the system, I'm finally going to be a convert and put the 05 system on my truck, I have the pump,rails,standpipes sitting in the garage so why not? Also there is a difference in the lower block dealing with the upper oil pan windage tray.

This was something I was thinking about earlier today that would correct that 2mm issue.

My point is, it can be done, but it's not a simple matter of R&R. The 03 specific parts must be robbed and re-installed on the 06 heads to make this work. Just like putting an 05 HPOP in an 03 block, EVERYTHING related to the 05 HPOP must also be put in. Doable, but extensive.