thought maybe i had an answer. for 1969 if the heater box was in a canadian car the part number was 2837501 in stead of 2837500. went back and checked to see if that was so for the 1970 and it was not. the number ends up being 2936068 (canadian) instead of what i am used to seeing 2936680. well you can see that in the above post. what is the build date of your car? maybe it is late in the model year. with mopar, never say never.