Okay, I'm mystified. Our 1950 AD pickup, which is titled as a 51 and is probably a 1953, has what appears to be a 55-57 pressure-oiled 235.
The casting number is 3837004. In the casting number pages, where most engines have the years listed, some have this casting as a 55-57, others as a T56X.
Google does not know what a T56X is.
To further muddy the water, on the serial number boss, it has F40IH. Possibly one, but probably "eye" in the 4th position. I'm pretty sure the third digit is a zero.
There does not seem to be any more serial number than this, and it doesn't fit with any serial number guides.
Any ideas?
