From the serial number (the stamped number) it comes out as a '54 235 built at Flint Michigan, and is a 3100 Truck w/manual transmission application. The other code (cast near the starter) is the casting date and which line it was on. The C304 breaks down to the block being cast on March 30 of 1954.
If they need the block casting number, it is located near the front of the block and will be a 7 digit number.


Bill Burmeister