After talking with Simp5782, it's almost going there. I did the stock air filter modification on my my truck and it turned into a beast! Well, I had my pump gone through for a leaking seal that was dumping diesel into the crankcase and they upped it 10% on the bench from factory specs. I had previously turned it up from the military and it wasn't even close to factory according to R&S Diesel who went through the pump. Now I guess I need to do the "Rainbird" filter mod as 74M35A2 calls it. We never agree on anything, might as well start a war!!! Not my intention as 98G pointed out but fair game once the deer walks out of the woods!
I think a turbo hurts the longevity of the engine. I honestly wanted a little more time at the rally and I would have let some folks drive mine to see a difference. It is not always about power. Granted, it is nice but you don't need to use it all the time. I like the fact that I can cruise 60 grossing 55 to 60,000lbs and get 5.5mpg the whole time. Some hills may drop me down to 47 or so but nothing you can't live with. Let's put it this way. These things weren't meant to climb hills very well over a speed of about 30mph. You put one in low range with 30k behind it and it will climb Mt. Everest at it's own pace.
I am happy by far with the fuel mileage in the loaded and unloaded category. 5.5 loaded with whatever it wants (in the bed, and/or on the trailer) and almost 8mpg towing the 11,500lb M322. As far as its reliability I have a good respect for mine. I did 4,200 miles in 8 days in it. Most of it was loaded with something. She didn't let me down. I think both engines have the same reliability though. I don't think anyone had any problems going to and from the rally. Some people traveled a long ways.
All in all IMO. If you are looking for a cruiser that is quiet and just a drive around hobby thing then an A2 is great. They are still simple and easy to work on. If you are going to be beating something up and hauling logs in and out of the woods and need the low end torque even though it may be at a turtles pace sometimes. Then stick with the 250.
I know all and all in people went to working with the mods that I have then they would have some different answers for their A2. It is what it is. Every horse needs an upgrade. Drive what you like and enjoy it.
And yes the rainbird system does work. I have no problem showing off my $50 Ram Air FUNCTIONING intake system.