Motor: In 87 I think there was just one engine available, the 2.6 4banger. I am a big believer in this engine as long as you keep the maintenance up in it, I actually used my 88 to pull a friends 93 f-150 ext-cab pickup about 60 miles after he broke down. Chocked the wheels on the trailer, put it in lowrange and it had the power to pull the ford up onto the trailer no problem. I wont like that 55 was all the trooper couldmanage pulling it home, with the ac off but it still impressed me.
The motor was probably about the best thing about the truck, it was only a 4-cyl but it had a good bit of grunt, stock 4.56 gears might have had a hand in that though. There was a limited availability 2 door shortwheelbase model that came stock with 32's and I believe 4.88's I think it was called the RS or the SR one or the other.
I never did to much offroading with it but going play in some fields with just The all terrains it handed mud better than my 4runner does with Remington mud brutes. Once I have my new engine in and have the gears to spin the tires with some authority that might change though.
Mileage: Mine running 31' all terrains got about 17-21 depending on how I drove it.
Reliability: I had nearly no problems with mine except that the valves needed adjusting about every other oilchange but I haveheard that Isuzu's don't hold an adjustment well. And I had two starters go out, I want to say on the 2.6 it was fairly easy to change the starter but on my 86 trooper with the 2.3 it was a compleat pain in the ass. The suspension and frame on the 86 and older models was made different than the later years and in my opinion was Much MUCH beefier on the newerones. The only reason i had bought the 86 was because I was going to SAS it but I found the 4runner and it was running so I dumped the 86 trooper.
Parts availability: All of the parts I ever needed for it I was able to get in stock at work (ex AZ employee... don't buy parts from AutoZone)
For 500 dollars if it runs and it has the 2.6 with a 5 speed I would do it. If you plan on using it as a daily driver it will do good at that, I remember it being very smooth driving. If you are planning on offroading it in mud it will be fairly good stock, the truck is very light and as long as you keep the tires spinning you should be able to skim over most anything withing reason. Anything you need to flex for goodluck with the stock IFS, I have seen some pics of Toyota IFS truck and the look downright limber compaired to any 4wd stock Isuzu.
