Using 04 heads (18mm) on an 06 truck (20mm)

I am going to be tearing my truck down and doing headgaskets myself finally. I have a buddy who has a spare set of 18mm heads sitting on the bench. They will be machined and ready to go so when I pull mine, I can just toss his on. Then I will just machine my 06 heads and give them back to him for him to resell. This will help make this a quicker process so my truck isn't down for so long, and so his lift isn't tied up for so long.

Anything I need to know about putting the 18mm heads on my 20mm head truck? I will get the dowel reducer kit ( 6C3Z-6B041-B ), and the 18mm gaskets ( 4C3Z-6051-EB ). What else as far as the heads are concerned? I've read a few things saying there were different length up-pipes? Any comment on that?

I think you've got everything in order honestly. I guess the oil rails/system and such were different on 03's?

Ok, I wasn't sure when they went from the straight rails to the wavy rails either. I'm putting together a list of all the stuff I need for this. Just bought an intake gasket set that included a TON of o-rings and gaskets, clearly more than I need or will use, but I figure more is better than not enough. Here's the gasket kit: http://cgi.ebay.com/ebaymotors/_W0Q...emZ260852375503QQsspagenameZSTRKQ3aMEWNXQ3aIT

OEM headgaskets (18mm)
Exhaust manifold gaskets
Kit for Dummyplug's and Stand pipes
updated STC fitting
20mm to 18mm dowel kit
Restore (1 gal)
oil cooler rebuild kit
HPOP screen (oil cooler kit comes with this)
IPR screen
Upgrade turbo oil supply line

I think that should cover it. Then just have to pay for head machining. Already have ARP's and a big bottle of the new ultra-torque.

I want to do this ONCE.

By the looks of it, it'll only be once since your replacing all the necessities. Good luck to you, I know how frustrating it gets sometimes.

Mdub707 said:

Ok, I wasn't sure when they went from the straight rails to the wavy rails either.

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Only the 03's had straight rails with different stand pipes as far as my experience goes. Every 04 and up 6.0 I've messed with had the wave rails.

Ok that's what I thought, haven't torn that far into many 03/04 trucks though.

My warranty is officially up, and I'm sick of the half-arse work the dealers have done. I'm doing it myself and hopefully, just this once!

Thanks guys!

colonyofdrones said:

Only the 03's had straight rails with different stand pipes as far as my experience goes. Every 04 and up 6.0 I've messed with had the wave rails.

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:whs: youll be good.

Great, now only if I can harvest that money tree out back out of season and get my truck back from the dealership, I'll be good to go... :doh:

Mdub707 said:

I am going to be tearing my truck down and doing headgaskets myself finally. I have a buddy who has a spare set of 18mm heads sitting on the bench. They will be machined and ready to go so when I pull mine, I can just toss his on. Then I will just machine my 06 heads and give them back to him for him to resell. This will help make this a quicker process so my truck isn't down for so long, and so his lift isn't tied up for so long.

Anything I need to know about putting the 18mm heads on my 20mm head truck? I will get the dowel reducer kit ( 6C3Z-6B041-B ), and the 18mm gaskets ( 4C3Z-6051-EB ). What else as far as the heads are concerned? I've read a few things saying there were different length up-pipes? Any comment on that?

Click to expand...

Idk if I'm too late but if you have a 20mm block you will need 20mm gaskets

Silverback said:

Idk if I'm too late but if you have a 20mm block you will need 20mm gaskets

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Not too late! I was just actually thinking about this since I have a buddy going through his gaskets right now too. So I need the 20mm gaskets, but still need the 18mm to 20mm dowels to hold the 18mm heads on? I thought only the heads changed, and the blocks were all the same?

Mdub707 said:

Not too late! I was just actually thinking about this since I have a buddy going through his gaskets right now too. So I need the 20mm gaskets, but still need the 18mm to 20mm dowels to hold the 18mm heads on? I thought only the heads changed, and the blocks were all the same?

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Correct

And nope the blocks changed too.

Really... that's interesting. I'm heading down to my buddies shop tonight who has the 18mm heads coming off, going to check them out. Not sure if I want to use them or not, they have something like 285,000 miles on them. The oasis on the truck is spotless though and this is the first time it's puked coolant. Or I can use my 20mm heads that are currently on my truck, but then I have the downtime of waiting on the machine shop and I tie up my buddies lift for a few days. Hmmm

Tie up the the lift. Short-cuts on 6.0s don't usually pay off. Just my thought.

I'm not sure how much of a short cut it is... even though my truck only has 90k miles on it, the cab has been off of it 3 times and one head replaced under warranty. His 289,000 mile 05 hasn't had the cab up or the heads off once. It only started puking coolant VERY recently after the addition of a tuner. There's a good chance his heads are better than mine.

It's also not my lift to tie up, it's his.

Just because your truck is an 06 does not mean it has 20mm dowls. I pulled the heads off of mine and it had 18mm dowls. The valve cover clearly says 2006 right on it so check yours out before you go ordering a ton of stuff. Just my $.02

thanks,
Ac

darklcdfeller said:

Just because your truck is an 06 does not mean it has 20mm dowls. I pulled the heads off of mine and it had 18mm dowls. The valve cover clearly says 2006 right on it so check yours out before you go ordering a ton of stuff. Just my $.02

thanks,
Ac

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What is the build year of the truck? I think i am running into the same thing. 2006 Engine and an 11/05 build date of the truck

My build date is later 06, I'm pretty confident it has 20mm stuff. Worst case is I have to order new gaskets and resell the ones I have I guess.

I've also had one head replaced already, so I know there is at least one 20 mm head on it, as for the block, I guess I'll have to research the build date a little more.

if its built after 1/15/06 it has 20mm dowels

To convert to the smaller dowel heads you will need to get the t-40 headed injector hold downs. The t-45 headed hold downs will NOT fit in those small dowel heads. The dowel locations and bolt sizes for the rocker carriers are also different between the early and late production motors.

Ok, the plot thickens. Just checked the door jamb on the truck to verify what the build date is/was. It is a 12/05 build date, so my guess is it came with 18mm heads. However one head was replaced under warranty, so I'm assuming I have one 18mm head and one 20mm head.

As for different bolts and injector hold downs, I believe we have enough for each size to do it no matter what is in there.