On your AC set up, my 1st thought was 76-94 has a lot of years between. The design might be the same, but the odds are there were probably running changes that occurred between those years. I'm sure suppliers were changed, and parts may or may not swap between the two units, but the two units may be able to be swapped as complete units. Maybe comparing the exchange of things like heater cores, AC evaporators, or blower motors might give you an idea of a year range those parts might fit as replacement parts, but sometimes those parts are adapted to fit multiple years too. It was not unheard of for Dodge to come up with a new design mid year, then engineer the new part to be a direct replacement for the old design. When they installed the last unit of old design part on the assembly line, the next vehicle in line, and every one after it, got the new designed unit installed as the line kept moving.

The 2nd thought was, Dodge reused a lot of stuff if something worked well. The only time they changed some stuff was when a better design came along, or something was no longer available for the old unit, or the government required something to be changed.

As an example, I believe the Torsion bars on my 91 Dakota 4x4 frame use the same torsion bars (only with a higher weight capacity) as are used on a 2009 Durango. The only way I am going to know for sure is to have one of both sitting on my bench to measure.

I believe your AC unit will fall under the same situation, the only way your going to know for sure is to take both units apart and compare them to each other, or stumble across someone that has already done that. You need to clean out both AC units anyway, right? Make a lot of noise around it, then ten minutes later make a lot of noise again, maybe those rattlers will get the message and leave? Be careful. Gene