Does any one know if the 6.9 IDI can be bored out to a 7.3 and could you use 7.3 heads once it is bored out ?

 

one of the more experinced guys will chime in in a minute but I think the're gonna tell you that the heads will fit but boring it out is just inviting trouble, not that bad though the heads gain more power than the bore job would

 

ok, i know part of it... a 7.3 IS a bored out 6.9... but anything else, help is on the way... sooner or later...

 

yea same block, from what I remember reading the heads are the same to.

 

The heads on the 6.9 have bolt holes for a 7/16" bolts, the 7.3 has them for 1/2 bolts. I am not sure if you can get washers (they are hardened) that will let you use the 7/16" bolts with the bigger holes.

 

A 7.3 is a 6.9 block bored 0.110 over.

Have your 6.9 bored 0.110 over and you got your self a 7.3

Beware the 7.3 has cavitation issues if you don't treat it.

 

The heads wont swap, I suppose you might be able to bore a 6.9 that much, but I wouldn't, as that is why I prefer the 6.9 over the 7.3. You can bore the 6.9 several times and still have better cylinder walls than a new 7.3.