I just finished my heater rebuild and thought I would pass on the motor info. I needed to upgrade the main motor to 12v. All the standard suppliers for classic parts had them for around $60 or more. I found one at O'Reilly Auto for $31. fit and works just fine. Part number was PM354. 12volt, 1/4" shaft with a sleeve to make it 5/16ths if needed. I could not find what I thought was a close enough replacement for the defrost motor so I am installing a voltage reducer. I bench tested it. I was suprised how hot they get. Yes, it is said to be big enough for a blower motor.
Here is my finished
heater. I know the color is not correct but it will look good with the black carpet going in my cab. I have the good 6v motor if anyone needs one.
