Heater box blower motor options?

This is in my 70 Duster which originally was an ac car. I converted the firewall with a patch from a non ac car and used a non ac heater box from a 67 Dart. I am positive that the non ac cars all had the wiring in the cockpit whereas an ac car would have had the wire connections in the engine bay. I did some searches on here before posting and it looks like I am not the only one not being able to find the correct motor. Am just hoping someone has found a remedy....