I found an 89 wrangler I'm thinking of buying. It's in exceptional shape and has several upgrades already done, lift, tires, wheels, body armor, winch and so on. The engine is a stock 4.2 with a 5 speed. It currently has 155,000 on it. My question is how reliable is the 4.2 and is there anything specific I should look for on this model? Frame and floors are also excellent condition. For $4000 I don't really see where I could go wrong but I don't know anything about the 4.2 either. Thanks in advance.