7.3 heads on 6.9 engine

[pontoonrob]

Hello everyone, I am wanting to make sure my heads off a 7.3 will fit a 6.9 without any issues. I asked this question and Gary mentioned a few members have already tried it. I had someone tell me that the 6.9 cups should be put in the 7.3 heads, Anyone know if this is necessary? I am going to stud the 6.9.can the precups be reused without issues?---Rob

 

[Knuckledragger]

The only real issue is the difference in bolt hole size, and that is not enough to get excited about. Make sure to use quality washers and you are good to go. I do not know that there is a difference in the pre-cups enough to make it worth trying to change them out.

There is a difference in the head gaskets (Gary will weigh in on this), the 7.3 have a block off plate for coolant in one spot. Since you are using 7.3 heads, this may not be an issue.

 

[TahoeTom]

http://www.oilburners.net/forums/showthread.php?46461-7-3-Heads-on-a-6-9&highlight=arp+200-8598
Check out this thread. The 7.3 head is thicker at the lower head bolt holes, so you will need to mill down to 6.9 height or source longer head bolts for that row. The 7.3 head has coolant ports plugged on the mating surface that are open on 6.9 heads. If a 6.9 head gasket is used, drill a hole in the plug to match the hole in the gasket.