The 1947 Chevrolet Truck Specifications manual (10-1-1947) shows at least one heater as an RPO for some models
(the chart instructions are as clear as mud):
Heater & defroster (fresh air) - RPO 385B (for at least some models?)
https://dl.dropboxusercontent.com/u/30524403/1947-Chevrolet-Truck%20RPOs.pdfThe Truck Data Books indicates this heater is available on all models of trucks (this is the "deluxe"
Fresh-Air Ventilator, Heater and Defroster).
That same 1947 Truck Specifications manual also shows three model numbers for "Heater".
Part Numbers ("UNIT IDENTIFICATION") and names:
986101 Heater Car (Deluxe)
986104 Heater And defroster (with fresh air inlet)
986102 Heater Blower defroster
https://dl.dropboxusercontent.com/u/30524403/1947-Chevrolet-Truck%20accessories.pdfA 9-15-1947 Accessories Parts List shows 5 heaters, but it is not clear which are available only for car or truck (or, available for both).
986104 is listed as: Heater & Defroster - Fresh Air 1947 Truck
986101 Heater Dash-Type is listed but car/truck is not specified
The Truck Data Book shows a "
Heater and Defroster, De Luxe" that is completely different from GM Advance-Design other heaters (no part number is given). It has two electric switches to independently regulate heater and defroster motors.
The EA Deluxe Heater w/ defroster referred-to in the original post, made by EA Laboratories, Brooklyn N.Y. USA, would have been a non-GM accessory heater (installed by dealer, owner, shop, friend)
