There is a number visible on the head on the drivers side, on the lower block passenger side on the pad behind the distributor is another. Post those here and one of the casting guru's will tell you what you have.
This is the pad you should find the number on.
https://www.flickr.com/photos/advance-design_parts_co/13994062018/in/set-72157631868452754

1950 Chevrolet 3/4-Ton 3600
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