On stock engine, with new S&B intake, H&S set to Hot Damn300, final run on trans relearn at 99% throttle she went to 45lbs! I'm guessing that if I leave it at that setting and drive it like I stole it(cause it's that much fun) that I may as well start lifting cab off right now? Any thoughts or personal experience on this topic?

 

Stock max from the factory is 41 lb's if I remember correctly. Set your defuels below the max so that doesn't happen. Personally I have my set at 33 Lbs. No particular reason other than that's more than enough for city driving.

 

H&S says 45 is OK periodically. Personally, my Defuel setting is at 32. No reason to exceed that in my opinion.

 

The Borg's on the 6.4 are pretty stout. Mine saw 52 psi a couple of times. My buddies 6.4 on 40" tires sees 50+ all the time. No need to worry about 45 psi for the turbos, it's the head gaskets that will hate it, especially if back pressure is high.

 

Ya, I went back out and looked and the defuel for boost was off, oops! I now set it at 40, probably should take it down more, but I feel there is a reason to keep it up pretty good- POWER! It is wild when it is fully lit!

 

40 would be a nice place to leave it.

 

41PSI is max. I ran that many times but anymore than that and you run the risk of lifting the heads.

 

UGA33- I assume your buddies with the big tires has a built motor? Or at least studded heads?

 

10-4 SENIX, I won't push it too much.
I got no problem with the fact that soon cab is coming off to stud it and take care of some other known issues such as unknown oil leak on driver side upper bank and little leaky up pipes(could sometimes smell raw diesel in cab pretty bad when regen would begin) but, would like to wait till summer

 

My 6.4 was studded and his is also. That's it. Both of us hit 50+ psi on non studded heads with no puking but when heads were taken off they were both a couple more hard runs from blowing. Wish I would have taken pics.