Basic questions aren't the same as having the ability to fix or repair, thus the reason for questions about something someone is not familiar with. I didn't know before talking to the guy selling the unit didn't have the answers for my questions.Maybe, just maybe, this could be a diamond in the ruff, who knows. So if my questions are so basic and my lack of knowledge upsets you that bad, maybe you should just overlook my ignorance.
So far your questions are so basic as showing you have not read anything on this forum and you're not aware of even basic things like transmission options AND you've asked questions about swapping in 4 speed trannies, which is a Herculean job. You've also said you don't feel comfortable looking over certain things and are requesting assistance. You also said you're not someone who wrenches or works on stuff.
You've been on the site less than 2 months and its apparent that even when looking for a car you don't see giant red flags when a HMMWV owner doesn't know things like 3 or 4 speed in his vehicle for sale.
You mention it might be a "diamond-in-the-rough", but you haven't even see it OR been allowed to drive it, AND the owner sounds like he doesn't want to let you drive it pre-purchase.
GIANT RED FLAGS.
I'm not here trying to beat up on you. I'm trying to save you a World of hurt and pain and $$$$$$.
Stick around, search the forum, read posts for the next couple of months, and silently lurk around to see the problems others are dealing with, ESPECIALLY with Winter weather on the way.
Buying an old Dodge is easy, you can have a dealership service it to bail you out in an emergency. Not so easy with a HUMMWV. And unless you're a Rockefeller, you will need to wrench or pay $$$$$$.
Just look up PCB and see that just a simple protective control unit, a unit that is essential to operate these rigs, is a $700 headache waiting to happen. Then look up my posts trying to wrap my head around creating a PCB bypass to see there is a lot to know just about this stupid little box that we cannot yet live without. Then there are stuck and broken glow plugs, power steering hydraulics used to operate power brakes, fuel pumps and fuel injection pumps that break down, stuck doors, broken directional controls, 24 Volt starters... The list is endless on these old vehicles that have been rode hard and put to sleep wet every working day of their lives.
SO if a guy has a car for sale and won't let you drive it and he doesn't know what kind of transmission he is running and you don't see red flags, I see a setup for disaster. You're the one I'm looking out for, not me.
AND, as you want to walk blindly into this lion's den AND you want to take insult in my attempts to help AND you make statements like "maybe you should just overlook ignorance", maybe you're missing the point and getting your skirt blown up for sake of not understanding.
Your choice. Buy a lemon from an owner who won't answer your questions, or trust some free advice that is warning you that you seem to be unprepared at this point in time to purchase a HMMWV because you need to do more homework.
Your $. And you know what they say about fools and $ and ultimate separation of the 2.
There is a member who reminds all that there are 500K HMMWV's out there, all waiting to be purchased by one of us at some point in time. There is no rush to have to buy one now. My feeling is why are you rushing things when at this point in time you don't even know what you don't know.
If you want, I will not bother you again, or offer advice and such ever again.