Depending on what part of the country you are in (like in the northern part, or the rust belt), I would check for rust on the leaf spring shackles/frame and on the leaf spring/axle areas. The front spindle area can sometimes be riddled with rust as well. Check your fuel lines that run along the inside driver frame rail.
Regarding the body itself, check the usual spots (wheel wells, floor pans). If it sounds mechanically fine, then I say go for it. You may have to spray the Idle Air Control valve (IAC) and Mass Airflow Sensor (MAF) with 2 cans of carb cleaner since it's been a while, but otherwise, it should be okay.
70K mi on a 91 is great. The 3.0L is very reliable, and an excellent contender for a vehicle or daily driver.
I personally wouldn't pay more than a couple thousand for it. How much are you buying it for?
And welcome to TRS.
Pete
