Here is some light reading (and, an absolute necessity):
A 1948-1951 Truck Shop Manual - available on eBay and from any of the reproduction parts members.

Also, get a 1951 Operator's Manual.

Both are also available on-line:
http://chevy.oldcarmanualproject.com/shop/1948_51truck/index.htm
http://chevy.oldcarmanualproject.com/chevyowner/51tomindex.htm

And, this on-line manual can also be downloaded (see link below):
http://chevy.oldcarmanualproject.com/chevyresto/51index.htm

Here is that manual, if you want to print it out (it is large - 10MB, maybe):
http://1954advance-design.com/chev-specs/1951-Chevrolet-Truck.pdf

By the way, welcome to Stovebolt.com (and, Thank You for serving our country).