6.9/7.3 head interchangeable?

[F350farmboy]

Are the 6.9/7.3 IDI heads interchangeable?

I ask because I've had a mostly complete '90 7.3L for over 2 years now and I'm gonna scrap all I cant use.

I already plan on keeping the rockers and injectors (to save them for to-be cores for moose injectors hopefully ). Anything else I should keep from the 7.3 thats better than the 6.9 and would swap over?

I would like to keep the heads and tool with them and get them rebuilt later down the road and swap them into my 6.9 when I get a turbo for it.

Sorry if this has been talked already, but I've searched for 30 mins with no luck.
Thanks

 

[F350farmboy]

Never mind.....forgot about the different head bolt sizes.

Anything else I should keep before I start scrapping/selling parts?

 

[towcat]

if I were you I'd save all the sheetmetal, nutz/bolts and the fuel pump ecentric if you are gonna scrap the motor.

 

[k_williams1982]

There are studs available that are 7/16" on the block side (6.9) and 1/2" on the head side (7.3). I was thinking about putting 7.3 heads on my 6.9 a little while back and did some research on the head swap. NAPA told me that they could also drill and rethread the 6.9 block for 1/2" bolts/studs. I haven't "forgotten" this idea, but I'm trying to make sure that all the coolant passages and stuff like that are the same before I stick a set of 7.3 heads on my 6.9 engine.

 

[typ4]

The dowel ring is the same for both engines, I see no reason they wouldnt bolt on. You cant drill and tap the block for bigger, there wont be enough thread engagement.

 

[david85]

The bolt lengths are different between the 6.9 and 7.3 heads. My machine shop tried to make some 6.9 heads work on a 7.3L engine because all the 7.3 heads they found were cracked. They drilled the holes out and tried to install them and then realized that they would have needed custom bolts to make it work. The heads are still at their shop a few years later AFAIK. Chevy guys.....

He offered to sell me those heads at a pretty good price rebuilt ant all, but advised against it after seeing how small the steel washers were on the 6.9 head bolts. We didn't think they could hold enough clamping force to be reliable long term. I guess I'll never know now because I went with remaned heads that I sourced from a supplier in alberta.

 

[FordGuy100]

The dowel ring is the same for both engines, I see no reason they wouldnt bolt on. You cant drill and tap the block for bigger, there wont be enough thread engagement.

Unless you went and threaded them for like 9/16" head studs

 

[typ4]

Sorry, I forgot about the length difference.