6.9 V 7.3

[LASVEGAS7.3IDI]

I know a lot of the parts are interchangeable but can you use 7.3 heads on a 6.9 block.

 

[seawalkersee]

Well...I guess you probably COULD do it, but the bolt holes for the 7.3 are larger than the 6.9s. 3/8 to 1/2" or somethin like that. None the less, you would need to do more than just put them on the engine.

SWS

 

[dyoung14]

I have been told that you could and i have been told you could use the 6.l9 heads on the 7.3, i mean there supose to be the same block so...

 

[GenLightening]

I have been told that you could and i have been told you could use the 6.l9 heads on the 7.3, I mean there supposed to be the same block so...

Except the 7.3 head bolts wouldn't go through the holes in the 6.9 heads....unless you machined them out big enough.

The 7.3 heads on a 6.9 block should work, the dowels to locate them should hold them in place. Or make solid ones to be sure.

 

[typ4]

Cant make solid ones, the bolts go thru the middle, they are tube dowels.

 

[GenLightening]

Cant make solid ones, the bolts go thru the middle, they are tube dowels.

Um, yeah.... I knew that.
I should have said "thicker" so the 6.9 bolts are a snug fit through them.

 

[FordGuy100]

You can't drille and tap the 6.9 block for 1/2". Just not enough meat. I still say tap a 6.9 block for 9/16" studs. No more blown headgaskets

 

[THECACKLER]

The 6.9 bolts are 7/16" and the 7.3's are 1/2" so that's a 1/16" diametral difference or .032" radially. This would slightly decrease the load bearing surface of the head bolt washer. I wouldn't be too concerned. I think the rub comes in when you select head gaskets. I would tend to believe that you would want 6.9 HG's for the Fire Ring diameter, but 6.9's have the coolant passages at the corners where the 7.3's are blocked. Even so, I'm sure this swap has been done, so maybe somebody will chime in.

 

[LASVEGAS7.3IDI]

forgot to add the block is studded so the bolts should not be a prob?