what size engine

[guy51usa]

I just bought 1957 GMC 350 truck and can't remember what size pontiac V8 came in it. I'm a dinosaur when it comes to tech so I don't have a digital camera or a scanner , hence no pictures to post. This is an old grain truck so has only 42k original miles and always kept inside, virtually rust free and the door hinges aren't even loose. bI bought it to use as a trash truck for my construction business but may have to eventually put the cab on half ton chassis.