Head differences

[Mikey89014]

Does anyone know the differences between a 83 6.9 head and 84 and up heads? I read they are not interchangeable. thanks, mike

 

[argve]

They are interchangeable - there were some changes but they were so minor that you wouldn't know about them unless you were looking at the spec sheet.

What you are probably thinking about is that 6.9 and 7.3 heads are not swappable because of the difference in head bolt diameter.

 

[icanfixall]

The early 6.9 heads had slightly differant precups and the compression ratio was slightly differant. This was not a big deal either but... The biggest reason you don't want the early heads is they had a tendency to crack easily. This was a known problem. The bad head casting number was 1805296C1. The better 6.9 head casting number is 1805855C1...

 

[Mikey89014]

Thanks guys,

The reason i'm asking is because i have a 87 block that i want to use 83 heads on. These 83 heads were rebuilt so know they aren't cracked. I have some 87 heads also that are not cracked, however they need a rebuild. The 83's are done with all new intake and exhaust seats and valves.. Mike

 

[argve]

Toss 'em on there and enjoy. Just follow the torque proceedure when installing.

 

[icanfixall]

Sounds fine but.... You know there is alwasys going to be a big but... These heads don't have exchangeable intake valve seats.... Only the exhaust are replaceable. If these early heads are as you posted then use them and enjoy. They will be fine till they aren't. Now there is no reason to think they wont last just like any other set. You need to trust the rebuilder on this.... Is your motor out of the truck. If so its much easier to work on. Make sure the surfaces are clean and the head bolt threads are cleaned with a bottoming tap.

 

[Mikey89014]

Yes the intake seats were added in the rebuild. I guess they were bad before the build. All 4 were replaced on one head, i havent checked the other yet though. And yes i took the engine out to check it because 3 glow plugs broke inside the right bank. I pulled it apart and all is ok, however i wanna use rebuilt heads off this engine on my 87 block.. Mike

 

[idiabuse]

http://www.enginebuildermag.com/Con...sue/11_01_2006/1539Ford73Lpdf_00000002084.pdf




enjoy the article


Javier

 

[87crewdually]

Be sure to use the 87 rockers. Earlier rockers are prone to failure.

 

[icanfixall]

All you can buy these days is the 7.3 rockers. The older 6.9 probamatic rockers are no longer offered.... And thats a good thing....

 

[87crewdually]

Thanks guys,

The reason i'm asking is because i have a 87 block that i want to use 83 heads on. These 83 heads were rebuilt so know they aren't cracked. I have some 87 heads also that are not cracked, however they need a rebuild. The 83's are done with all new intake and exhaust seats and valves.. Mike

All you can buy these days is the 7.3 rockers. The older 6.9 probamatic rockers are no longer offered.... And thats a good thing....

His post is the reason why I said to use the 87 rockers. He didn't say anything about buying new ones.

 

[icanfixall]

I kinda thouth thats why you posted that about the rockers. I was just adding the fact about onlty the newer rockers are available these days...