I have always been told diesel engine life is directly related to gallons burned. . So more hp= shorter life... we would probably all agree there. Its not uncommon for large engines to use gallons burned for service intervals for that reason. Another thing I have seen Cat do on their marine engines is a "cat" hour meter. On the 3406C (E rated) my dad had in his commercial boat 1600 rpms turned the "cat" hour meter at a 1:1, less than 1600 rpms it turned slower, and faster it turned faster (i. e. 1 hour at 1900 rpms would be more than 1 cat hour)...
So where is the OP now? Sounds like he is just stirring the pot to me.
So if a mod increases hp and also increases mpg (less fuel burned) = extended engine life? Not sure there is a definitive answer for mods vs engine life. But do agree that OP is probably sitting back and laughing at the pot he has stirred! :-laf
For info on truck ive added it as for the mileage 60,000 of rv trailer pulling trailer weight is 10,800 dry and the wife loads the kitchen sink and everything else that she needs or not. dont have the total weight (it might scare me) Ive driven large trucks most of my life and think that ,along with the cost of parts to repair my dodge makes me keep my foot out of the turbo. dont get me wrong I would like to have the power but just dont like the repair bill. And the milage on a trip to colorado last week at 14 miles per gal was nice also even if I dont have to pay for the fuel (I haul gas for a major oil company and if I get it rite they give me free fuel )so dont take it wrong for what I said just some have allot of issues with trucks SORRY!!!!!!!!!!!