94.5 was the last year for the IDI diesel (7.3). If it is an uato trans then it has a computer to run the trans but the manuals were totally mechanical. They also offered these trucks with a factory turbo option (these are pre powerstroke).
1994 was the last year for the IDI Diesel witch uses no electronics, just 1 single wire for the fuel shut off selonoid to turn the engine off. 2 versions were available that year, non turbo and factory turbo.
Cavitation was a problem with the 7.3, do a search for SCA additives and Cavitation in this forum, you'll find PLENTY of info on that subject.
Nothing else really, very simple and cheap to maintain trucks! Make sure you see the truck COLD (as in not been warmed up before you getting to it) that could mean hard cold starts problems, witch are usually easy and cheap to fix.
Now since you really don't want electronics, you'll have to get a 5 speed standard truck, as the only auto tranny for those years was the E4OD, and relys on nothing but electronics. If you go a lil older, saw late 80's and older, you can get one with the C6 3 speed, 0 electronics on that tranny, and very tough but no OD....