Wouldn't be any more than a typical OHV 6cylinder. Pretty cut and dried. The top end of these things are pretty simple to work on. The Buick 3800 that we use is tough. If the rings are good, and you're only talking down to the heads, I'd risk it. Do a compression check first, wet and dry. If wet is good, and dry is iffy, buy it with one thing in the back of your head......that'* alot of miles, even for a 4T60-E Trans. THAT'* where the money comes in.
I've heard of these things going longer than that 94 has, but it'* a car-to-car thing. Some will, some won't. Make sure you check for oil leaks under the lower intake, and ask about coolant loss.