The late 80's was a transitional period for MTB's. By '90, alot of them were becoming more specialized for off-road use. That is, fewer hardpoints for racks, fenders and such. Also, they were going towards thicker tubes, especially the forks, which had reduced forward rake. This made for a stiffer road ride which may be a little less desirable, but you can beat that with tires/pressure.

Also, it seems that the mid-level late 80's MTB's had the most hardpoints. The upper-end bikes being more off-road oriented.

This mid-range 1988 Trek 830 has double eyelets front and back, two bottle positions with room for two more, slender road friendly fork tines with rack bolsters on the forks. Also, it came with a BioPace/Ovaltech good quality Sakae forged crankset. The rings were stamped from plate, then machined to form. The tubes are also very slender and road friendly. The drop outs are forged as well. Unfortunately, one of them is broken. Not bad for an '88 Trekwan bike. BTW, those are the strap-on Planet Bike fenders even tho there are eyelets aplenty. The chainstays are as long as country road.
http://i13.tinypic.com/452ixyw.jpg

This bike is an upper-mid range '92 Trek 930. Note the much heavier and straighter fork tines. Only single eyelets up front with no rack bolster. Much stiffer bike on the road. Slightly shorter chainstays, but still long. It is US built of American True Temper tubes which is the same as Reynolds 853. A very good lugged frame that originally came with sorry-ass Altus components. The rings were stamped from sheet metal, then brake-pressed to form. I swapped all the stuff off the 830 onto this bike, including the excellent old Shimano Light Action thummies, set to friction. I would avoid the possible mechanical issues of rapid-fire trigger shifts for touring.
http://i13.tinypic.com/3yofrdc.jpg

Seriously considering sweating out the dropouts on the old 830 and installing some new ones. That bike was a great century maker and I wouldn't hesitate to take a modified MTB anywhere.