1970 Duster Alternator Pulley Alignment

I'm assuming you have a '70 and newer engine setup. If so, yes, the crank pulley is different between A/C and non-A/C. So is the water pump pulley. You might be able to get away with keeping that water pump. I'd try it and see. The difference is the number of impellers on the inside of the pump. You can keep the alternator, you just need to change to a single groove pulley or press the existing pulley on so one of the grooves lines up properly. To be completely stock, you should have a rigid fan on a non-A/C car, not a clutch fan. The clutch fan should work fine however.