I had Yancey Power do the service on mine when I bought it from Ft. Gillem. The guys in the shop loved it and it tuned to spec perfectly and runs like a demon. I also went sight unseen on my truck. I had my brother go look at the truck and he basically said it looked like a truck and that was good enough for him.
I got a truck with 6300 miles and 497 engine hours. Now the guages are almost always wrong and can be swapped without regard to proper tracking of hours or miles. The Cat 3116 needs an overhead performed after the first 500 hours then every 2000 hours after that. It can easily be done for under 500 dollars by a willing Cat dealer. I checked some RV websites and folks were getting it for $400 out the door. It is money well spent. You will take forever to get 2000 more hours on a deuce so you may never need another service as long as you own it.
Here is what I learned after picking up the truck.
1. The tac had been replaced with one that had a very similar amount of hours and the miles were correct. (I found several dispatch sheets under the seats from the last four years that noted miles and hours and maintenance performed) The tools and jack were missing and the forms as well. I replaced those, they might let you swipe them from a nearby truck.
2. The flat/low tires were mostly CTIS related. The truck had two brand new front tires and four original rears, one rear leaks down in 10-14 days to 15psi. All of the tires were good with more that 50% tread left. Some folks have gotten all new tires or all used depending on miles and if the truck was going to deploy.
3. The CTIS system is interesting when and if it works and is really a non-issue. If it is off it causes no problems and you air tires the old fashioned way like everyone else. Mine worked for three days then started alarming, I shut it off and left it off and love it off. No air leaks with it off BTW.
4. I had the trans serviced by Cat. They replaced the filters inside and out and swapped it to ATF from motor oil. It runs 20-30 degrees cooler and works fine. It is a hard tranny to break if maintained. I have read one post from a guy with an A3 and he ruined the trans abusing it. It does shift a little odd, kind of hard and soft depending on it's mood. But overall they work fine and are tough to hurt.
5. The engine has an oil weep from one seal that is very minor. Otherwise it was like new, the mech who worked on it was impressed with the condition and how well it ran. I replaced all the filters with Cat filters and had an oil change. It used a quart of oil over the course of my cross country recovery and the oil still looks almost new.
I ran the truck 60 hours in the next week and 2600 miles cross country with no problems. I kept 48-50mph and it ran like a champ. Doing the services and going for a couple of hour long drives to check things out was a good suggestion that I got from here and did as well. The bodies and beds are all M35, not new. They have been cleaned, repaired and painted but they are still the same old stuff. As long as you expect a M35 you are ok. Mine has a sprung tailgate and a small ding here and there and the bed is a little rough in one spot from some old rust eating it.
I bought a new alternator belt, radiator cap and some other small stuff to replace worn or aged and cracked bits and pieces. Like most military stuff, it has been sotred outside for years and the elements do get to stuff. If you get a truck this summer, bring wasp spray,,haha. If it has been sitting they are nesting someplace.
If you cannot get a guy to go check the truck for you, then go look close at the pics. I bought a truck advertized as "Running" and called the local DRMO guys. They said it would be running when I picked it up and had it idling with the tires aired up when I arrived. Most of these trucks are low miles and the engine trans combo had a 150,000 mile/three year warranty when they shipped to the Army. My truck was built in Sept/Oct 1998 according to the tags, thus is is really 12 years old.
As always, past experience does not mean you will get a good truck. But in my case I got a winner and most guys have. Guys who got trucks missing guages, headlights, batteries and switches have replaced them and drove home with no problem.
Good luck, I think mine was well worth what I paid. You cannot put super singles, power wipers and power steering on an A2 for the price.