Welcome and congratulations on finding the truck of your dreams (literally

).
I'll second John Milliman. I'm working on another project for my wife by a car manufacturer whose name is less than popular with Chevy owners. While the long range plan for that car is to modify the engine some, to start with we just want to get the current car and engine in good working order. I figure that I can always make the mods later if I want. Of course if the engine that is currently in your truck needs significant repairs, it may not be worth it to you just to see if you like it unmodified. But, I urge you to hold steadfast and not start chopping, shaving, etc. A 53 Chevy looks great stock and those kinds of modifications are irreversible. Finally, as others have already said, don't take the original engine to the dump. I'm sure you can find someone who wants it locally or on this board for a restoration project, and once it's gone, it's gone forever.