I don't think i would just leave it alone because the 2366 that we had before the one we have now blew up!!!!!!!
It was stock to. on it the valve lifter broke in the middle of harvest it only had 420 hrs on it!
i think that case pretty much has that 8.3 maxed out but then you look at the Deere that is getting 265 hp out of there 6.8 L
We have a 99 2388 that we turned up 40 horsepower. Didn't like it so we turned the screw up again ourselves. We did this 5 years and 2000 hours ago. Still runs like a top and never have seen any problems.
We will burn a full tank of diesel in a 12 hour day, but we are also running a Hillco leveler which adds about 10,000 pounds to the total machine weight (thats the reason we turned it up). As far as how we know what the horsepower is, NO IDEA. The first time we turned it up it was done by our local dealership, and it was estimated, but when I went up with the screw driver I just guessed. We added a pyro and boost gauge to keep an eye on things. Our main issue has been on hot days when the air to air can't keep up. When its above 100 you have to back off the hydro, but if you keep an eye on it we have had no problems. Blow out your radiator every day, keep an eye on the exhaust, and go like heck.
We also wired the waste gate on our turbo closed so we build all the boost possible. Keep a close eye on the machine and you should have no problems.