Thanks Randy,
You are right. I located the casting number as well as a date code of K188.
So now that I know what I have is this a logical unit for a 52 1/2 ton? The engine that came with it is a 216 out of a 53 car matched to a 58 powerglide. That is as far as the PO got. he didn't bother to match up a drive shaft which shouldn't be difficult.
This is not going to be a street scortcher but I don't want it to fight to have to get out of it's own way.
Opinions would be appreciated.