According to the 47-54 Factory Assembly Manual,
Section 7, Sheet 3.12
Hydra-Matic Oil pan cooler was used on the 3800 & 3900 models.

3800 model: Rear Oil pan cooler hose was snaked up the fire wall over the valve cover and connected to a nipple, locate on top the head. Just behind the temperature sensor, above the rear exhaust port on the head.
Here is a Picture of temperature sensor hole, on this truck the hole for the rear pan hose was plugged and the REAR PAN NIPPLE was looped together with the front nipple .

Front Oil pan cooler hose was snaked up the frame/passenger fender skirt and connected to a nipple on the water pump.
The front oil pan hose is the inlet into the oil pan.

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Plate on tranny: 200 CHC 54 13?3 Black plate