Sears Gas-Fired Furnace Model # 867.763461. Pwr Vent Damper Model # 867.763471. Operator, Part # 604636, worn out. Sears has one for $155.00, I want something less expensive. Any suggestions? BTW I've run the furnace sense 1981 and the Pwr Vent Damper quit working 1990. I recently decided to try and fix it because small amount of outside air invades the basement.