Update in post 13: it looks like this will work with the adapter dowels. I ended up returning this junkyard block and getting mine machined, so I don't know for sure it would have worked, but it looked like it would have. I would have gone through with this if one of the cylinders hadn't been messed up, which I should have noticed when I bought the block.

I just picked up a used block and think I might have a problem... It has larger dowel pin holes than my 2005 does. For some reason, the dowel pins are gone, though. It was supposed to be a 2005 block, I'm guessing it's a later one.

My 2005 block dowels are about 17.6mm OD, the holes in the used block are about 19.6mm. This makes me pretty sure they're the 20mm dowels. Do the adapter dowels 6C3Z-6B041-B make this work? Or am I screwed? It seems like those adapters might only be for a 20mm head on an 18mm block, not the other way around. I have the opposite - 18mm heads and a 20mm block.

Link to a place that sells dowels adapters... https://puredieselpower.com/ford/for...apter-kit.html

 

To think about it another way, what would Ford do for an early truck with 18mm dowels if a repair required a short block swap, like a bed plate leak that could not be resolved by resealing?
​​​​​​They'd be trying to use a 20mm dowel short block with 18mm heads, right?

 

Are you sure the 19.6mm isn't for an 18mm pin? That's less than 0.040 per side. That's obviously not super tight, but maybe it doesn't have to be? I don't know enough about engines to understand exactly what the pins are trying to line up.
I do know that I've seen straight pins applied when lineup isn't critical to the thousandths of an inch. If it is, tapered pins are usually applied.
It would also be very difficult to shoehorn a 20mm pin into a 19.6mm hole.
Assuming it is a 20mm block, I guess you'd either have to install pins in the block first, or line up and ream both out to a larger diameter. I'm no help on whether either can be done.

 

I asked m-chan68 to stop in and comment on this issue.
One would think you could just turn the adaptor upside
down. But you never know unless someone has tried it
and can say YES or NO. The other option is just try your self.
After all you will need the 18 to 20mm adaptors anyway if it works.

 

Thanks. It's a bit frustrating that all the sites that sell the adapters don't describe what they adapt...

I'm hoping I get some direction this weekend. If not, I'll probably order the adapter pins Sunday night so they ship Monday. Worst case, it's a $40 mistake... Well, really it could look ok and then become a bigger problem, but I'm an optimist... I might be able to get a friend to turn them on a lathe if necessary.

 

Send a PM to m-chan68, bismic, FICMrepair.com, ROBBINthaHOOD, run6.0run or Runs-wifey
and see what one of that bunch thinks about the problem.

I would think that one of them would have a good answer.

 

After January 11, 2006 are being referred to as "Commonization Engines".

The cylinder head gasket is also new to accommodate the new 20mm cylinder head location dowels.

Pre commonization heads use 18mm dowels

Note: The new cylinder head assembly is not interchangeable with the previously level head.

Cylinder Head Alignment Dowel Adaper Kit (18/20mm) – Ford 6.0L PowerStroke. Mahle-Clevite #GS-33593 (Qty Of 2 Dowels)

 

Using 04 heads (18mm) on an 06 truck (20mm) [Archive] - PowerStrokeArmy

http://powerstrokearmy.com/forums/ar...p/t-46449.html

http://southeastcylinderhead.com/for...ylinder-heads/

 

I read through that, and the guy found out his 2006 is an 12/05 build date, and has 18mm dowels in the block and one 20mm head, one 18mm head. He said he was going to put 18mm heads on it, and never reported back after saying he was about to do it. There's nothing definitive in that thread, unfortunately.

Also some people say you need to match the head gaskets to the block dowel size; others say match it to the head dowels. I'll definitely report back with what I end up doing...

 

Read the other thread also. You need different injector hold downs.

Also, head gaskets match the dowel size of the head

 

I'm reusing my heads, so I thought the hold downs would be the same (reuse my entire heads and their components).

 

Well, there you go then.

 

I got the adapter dowels. It looks like it's going to work. They are the perfect size for this. I tapped them into the block w/ a rubber mallet, and they slide right into the heads. The larger OD part does not stick up above the block surface. I measured the diameters and lengths of the 2 sections and they will not be a fit problem. The only remaining question is if 18mm head gaskets will seal well on a 20mm block with this setup, but it looks promising. 1mm larger radius around the circumference isn't that much...