quick head bolt question

[sootman73]

will 7.3l headbolts work in a 6.9l? i was pretty sure they do but wnted to know for sure. a guy asked me on ebay and said that 6.9l bolts were 7/16" and 7.3l bolts were 1/2"? im not for sure enough to tell him anything before hearing from here.

 

[OLDBULL8]

will 7.3l headbolts work in a 6.9l?

Absolutley NOT 6.9 bolts are 7/16"-14 7,3 bolts are !/2"-13 You couldn't even drill and retap a 6.9 for the 7.3 bolt's.

 

[icanfixall]

The above is very true but... Drilling out a 6.9 up to 9/16 will work. At least there will be enough metal for a complete thread in the block. Then figuring out if the 6.9 heads can handle the drilling out and not hitting a water jacket is the next hurdle. Drilling a 7/16 bolt out to a 1/2 inch bolt will not leave enough metal for a complete full thread. The hole size for the 7/16 bolts is already too big after the threads are cut.