OK - Your product was built a little before my time with Walbro as I am a lot more familiar with electric in-tank pumps. What you have is an AC Delco pump - from the AC in the part number. I assume it is a mechanical rocker arm diaphram pump feeding a carburetor on the engine. Since your interface is mechanical it would probably leave a hole in the engine that you would have to cover if you switched to an electric pump although that is entirely possible.
On Ebay there are many mechanical fuel pumps from AC as well as Carter that should work. The problem is going to be the mechanical interface and getting the right one. AC (or really GM) changed part numbers whenever they did a change rather than just a letter at the end of the number and therefore it is hard to find anything by the part number unless you have their matrix. (A very confusing system!) The good thing is that any fuel pump will have the capacity to supply your engine so you do not have to worry about the interior - only the interface. My suggestion is to take a photo and measure the interface - bolt hole pattern, arm length, etc. - and contact the seller on Ebay of one that looks about right. Typically a good seller will confirm the interface. The other option you have is to go to a Ford, since it is a Ford engine, or GM, since it is a Delco part, and have the part number traced to a current replacement part number.