I am looking at a 1987 Jeep YJ Wrangler for my son, it has about 141,000 miles on the 4 cyl. engine wih a new head gasket and milled head. Is there a history with this year Jeep? I seem to remember something about AMC and bad 4 cyl engines, but alas I am a Tacoma driver. Please, any input is welcome. From the description and pics it looks straight body wise.
The 2.5L is an AMC design which dates back to 1984. It will be a TBI version with around 116-118hp when it was new. The transmission will either be an Aisin AX-5 5-Speed or a 30RH 3-speed automatic. If it's an auto then it will have 3.73:1 gears. If it's a manual then it will have 4.10/4.11 gears.
The axles will be a Dana 30 Reverse with a vacuum disconnect and the rear will be a Dana 35c. The early YJ's (87-90) will have 10x1.75" vented drums out back and no C-clips. The +90's will have 9x2.5" smooth drums.
Nothing really inherently wrong with an '87. But then a later model, like a 1991 or newer would be better. The 2.5L got MPFI and was upped to 123hp which makes a difference with such a small power band. The pre-94's will have an internal clutch hydraulic bearing which has been known to leak. Still with 141K, I'm sure it has been replaced at least once.
Typical rust areas are the lower corners of the front windshield as they aren't galvanized. Leaking from the cowl seal under the windshield frame is also fairly common. This usually leads to the instrument panel rusting. You'll also want to check the frame for rust as well. The front opening and the rear near the shackle hanger are the usual areas.