There were only 300 '53 Corvettes made. You have an engine from one of those!
I would not install that in a truck.
There are only 225 '53 Corvettes known to survive. I bet one of those guys would pay a pretty penny for a correct '53 Corvette engine.
Carl you may be right, they made the last 1953 Corvette Christmas eve of 1953, number 300, however the stamping looks different for the alpha numbers versus the numerics. It is not unheard of people re-stamping blocks to increase the value of their otherwise very limited production vehicles. To me this looks like a re-stamp though.
Look at this 1953 of my Chevy 3100, see how the numbers and letters are similar?