Send us the casting numbers and we can tell you what you've got. I'd also look it over very carefully for cracks and any rust that might indicate a crack you can't see with the naked eye.As a preliminary step, this is important. If you end up getting it, you're going to want to have it checked over and probably have it magnifluxed and checked out internally in addition to planing the surface where the head mates. Take a look at the cylinder walls as well.

1953 Chevy 3600 3/4-Ton