head studs

[82fordtruck]

Can we get 1/2" UNF bolts/studs on the head end?

If so, then you could drill the block out to 29/64 and tap 1/2" UNF. This could help address the issues with head gaskets on a 6.9.

What do you guys think of this?

 

[icanfixall]

Well... Drilling out a 7/16 bolt thread will not give you a complete 1/2 13 bolt thread. Try it on a piece of scrap if you are not following what I mean by complete thread. Besides, the heads would need to be drilled out farhter than 1/2 inch and that may not leave enough meat around the holes for the coolant. It may leak.

 

[82fordtruck]

I agree - I am talking about 1/2 - 20 threads.

The drill for that is 29/64, which is 1/64 larger than 7/16.

Also, I have no idea what you mean by 1/2" threads being larger than 1/2". the drill is the minor diameter, and the tap brings it to 1/2" major diameter. If there is enough strength on a 7.3 here, then it should be fine on a 6.9.