A Script GPW with a very rusty body.
https://losangeles.craigslist.org/sfv/cto/d/coarsegold-1942-ford-gpw-jeep-project/7466880372.html
“1942 Ford GPW Script Jeep chassis (non-running), parts and body (rusted).
Serial number 30579
Engine Number: 37273
Includes: starter, carburetor, fuel pump, radiator plus many parts”
That looks like a 1940 Americar block. It fits, looks ok, but it is not a GPW motor.