well I know taht up til (and including) 93, the Dakotas were mechanical and 94-up are electronic. the 93-older have a speed sensor with a 2 wire plug for the computer AND a thread on fitting for the cable, 94+ they eliminated the cable drive.
If you see the 2 right next to one another you can tell a slightly different "font" to the odometer digits between them.
I have had 89,
90,
92 (still do)
93 (miss that one, it was a 5 speed truck)
94, and
96 (just bought, this one's 4X4) Dakotas.
so I can tell from what I remember that mine have had.
(unless it's a 4 banger) 93 was also last yr for 2 line (feed/return) fuel system and also last yr for inline fuel filter.

I have to look, I know I still have a good 94/95 computer for a V6, MIGHT still have a 93 one. Not saying that's your issue but just mentioning just in case....