Re: 87 grand wagoneer/poss.purchase
Definetely inspect the frame around the gas tank. It is prone to letting water and gunk trap in there thus rotting the frame (coffin rot) very common on all G-wags. Other problem areas are all the power goodies; seats, windows (especially the rear window), locks, cruise, AC, etc. With the 360 cid (5.9L) check for rear main leak (a possibility). If you can crawl under it, you might verify what t-case it has; NP228 or NP229, should be a NP229, but I have heard from a few guys that have bumped into other things in later G-Wags. Also (while you are there) look at the rear axle and see if it is a Dana 44 or an AMC 20, most common would be the AMC 20, but there have been some G-wags reported with the D44 (Bonus!). Under the hood, make sure all of the emissions stuff is there. You should see the EGR at the back of the manifold, smog pump on the driver's side to the side and below the P/S pump and A.I.R. valve behind that with three fairly large rubber hoses on it and the AIR tubes coming off of the exhaust manifolds, a charcoal vapor canister on the passenger side below the AC Compressor and on the fender. The Vacuum stuff will probably be a rats' nest, but that is typical.
I hope this helps
Phillip J. Van Why
1985 Jeep Grand Wagoneer