I would strongly consider replacing the heater core inside the heater box since you already have the dash out (approx. $65.00). But you will have to completely pull the heater box out also....no big thing at this point. Also change both hoses going to it with new. You probably don't want to have to remove the dash again anytime soon, so I'd consider this very carefully if you're not sure of the condition/age of this core/hoses. Change out that stinking heater valve back of the engine also. I don't know why you pulled the dash either, if all you needed was a heater blower motor. I've run car without a dashboard in only in the driveway for short period. No fuses were in the boards except the fuel pump fuse. This was a partially stripped parts car.
Good luck
