I was told that a Transmission from a 1992 Dakota 3.9L wont work correctly in a 1996 Dakota 3.9l becasue of the electronics? Is this true?

 

Yes. '96 and above had an electronically controlled governor valve and electronic speed sensor. The '94 and '95s had a hydraulically controlled governor valve and electronic speed sensor and the '93 and older had a hydraulically controlled governor and cable driven sensor.

Now I will say that the hydraulically controlled governors in the '95 and older will function properly in your truck, but it will trip the check engine light, the problem you may run into is the speed sensor not working.