I'm sure someone has thought about this already, but I couldn't find it so here goes:

You can't argue with the old horsepower mantra "There's no replacement for displacement" . That being said, what are the possibilities of boring and stroking the 5.9 utilizing the reciprocating parts from a 6.7? No advanced emissions problems, no ECM issues, just a good old-fashioned 5.9 with a bit more "umph". I'm not saying it would be cheap, and God knows I can't afford it, but what are the pro's/con's? Would it be cheaper or easier to put a modified 5.9 head on a 6.7 bottom end? I'm just thinking random thoughts and want some insight from the folks who live inside these blocks.

I was also thinking that a simpler, lower-buck alternative might be a 12 valve with the 6.7 parts...no ECM to mess with there, and the head should only require a deck to remove the old bore ridges...

Thoughts?

 

https://www.dieseltruckresource.com/...light=stroking I did a search of stroking and some other threads came up as well....should get you started anyways on your answer