The biggest risk on these is the rear axle. You should be ok for moderate wheeling with open differentials and 31 inch tires. If you lock and/or go bigger, You can upgrade to a Dana 44 if you find a cheap one available. A lot of people have good luck with the Ford 8.8 rear axle.
Check your Dana 35 rear axle model number. You need to know if you have the c-clip design or not. One version will hold the wheel on if you break the axle. The other will not.
You should be ok for a little while as long as you are light on the gas. If you do a lot of offroading, you eventually WILL want lockers. But right now I would recommend:
1.) If you're going to be in the backwoods by yourself, invest in a winch (5000lb is just barely enough, get more than 8000lb so you don't have to unspool the entire roll every time), winch plate, tow recovery hooks, snatch block, tree hugger, D shackle. Practice with your winch before you need it...Watch youtubes of other people's winching techniques. Some of the new (expensive) winches even come with onboard air for putting air back into your tires to go from offroad to highway! There is a saying: "Locking differentials get you further in... A winch gets you out"
2.) get a CB radio in the cab and an extra handheld now, and/or ham radio after passing your FCC Amatuer Radio Technician Class Licensing Exam (~$15 maximum). find your next exam here: http://www.arrl.org/find-an-amateur-...e-exam-session
. study for it here: http://ncvec.org/downloads/2014-2018%20Tech%20Pool.pdf
. In an emergency, you want an FCC licensed radio tech to help you, not a CB nut job. CB is not just for emergencies, people may also try to guide you over obstacles over the CB radio. The handheld is for your passenger to get out of the cab and check the path, obstacle, or depth of the water you are about to ford. Usually one CB radio is required equipment to go with clubs and groups. Practice with your radio before going out.
3.) Always carry A wool blanket, hiking shoes, tarp, and a couple days of MRE type rations, plenty of water (during survival mode, drink the water yourself. You can always pee it back into the radiator if need be). You can always hike out.
4.) Basic tool box. Sockets, ratchets, open end wrenches, duct tape, screw drivers, alan keys, zip ties, flashlights, breaker bar, jack (some people love/hate hi-lift jacks), etc
5.) Basic Maintenance: Is everything up to date? Champion Copper plugs (Not platinum!),wires,distributor,FUEL FILTER, air filter, oil, oil filter, Throttle body clean, IAC valve clean, transmission fluid (change after water crossings!), transfer case fluid (change after water crossings!), differential fluid (change after water crossings!), Coolant full and clean with enough distilled water in the mixture, Windshield washer fluid (needed for mud splatter!). Brake fluid and clutch fluid must be fresh, if it is old, change it! check your brake pads, rotors, shoes, drums. Check vent hoses are attached to transfer case, transmission, front differential, rear differential and that they are clear of obstruction so your moving parts don't fill with water or mud.
6.) Extra fog lights and driving lights or LED light bar. This could be optional depending on how far you go and what time you head back. If you get stuck out there and nightfall hits, you may have to spend the night if you don't have enough lighting. Rock lights are also a good cheap addition to the bottom of the jeep. Can't get over the rocks if you can't see them...
Some people carry drive shafts and crank position sensors. I think that's a bit overkill unless you are sharing and coordinating what to bring with a large group.
Most important thing: Drive your jeep A LOT before taking into the back country alone. you need to shake the bugs out. You don't want to get out there and find out that the previous owner patched an oil leak with bubble gum.
If you want to go do some easy to moderate off roading with some other jeeps, go right ahead. Just make sure there is someone to tow you home until you have all of your ducks in a row.
It's hard to tell if your steering is ok without seeing pictures. Is it driving ok on the highway? any play in the wheel? drifting? tracking straight? Any Bump Steer?
Best you can get from a 2.5L
No problem, 31 inch tires are about as large as you can go at street speed, you only notice a difference between 2.5L and 4.2/4.0L on the highway. If you're really into wheeling, consider purchasing two sets of wheels. You can Calibrate your speedometer for the street, and put bigger wheels on for offroad. Your 31" may be all you need for your purpose, I have seen some jeep jamborees require at least 33" tires and one locker. it depends entirely on what you will be doing.