Great question, and one thing I might add if you have not addressed it already, is the clearance between the fan to the radiator. I'm not sure how a 1938 truck is set up, but for example on my 261 that I am putting in my 1953 1/2 ton, I had to use a special adaptor plate on the front of the engine that moves the location of the water pump about 2" to allow it to be centered in the middle of the radiator, and also had to use a short-shaft water pump from a 216 engine. Just something to think about.


-Patrick
1953 Chevrolet 3100
261 / 4-speed / 4:11 / Commercial Red