Dart heater box interchange

So after looking a little closer I am thinking there are more differences than I originally thought. Though the case appears close to the same, the cable locations are a little different which could possibly pose an issue (one in later boxes is between the heater tubes while earlier has the 2 closest to the vent door) and the plug for the resistor has 2 prongs vs 3 on earlier boxes. Could be made to work I'm sure if mounting is the same but I'll probably just keep an eye out for a clean box or just repair the door on mine. Thanks A-body for the help