I borrowed a 5-gallon gas can and filled it up with 100LL. Then I took it home and dumped it into my fuel tank, and turned on the fuel pumps. It turns out that there were a couple of minor leaks, but they were because some of the fittings hadn't been sealed or tighted properly. Once they were taken care of, it was time to raise the nose up to a 15-degree angle, disconnect the fuel line from the carburetor, and see how long it takes for each pump to fill a 1-gallon container. My fuel consumption is predicted to be 10 gallons per hour (max), so the pumps need to be able to supply 15 gallons per hour (min) in order to make sure the engine is never starved for fuel. Fifteen gallons per hour is 1 gallon every 4 minutes. Fortunately, each pump running individually would fill a 1-gallon container in about 2 minutes, while both pumps running simultaneously would fill that same 1-gallon container in just over a minute! I'd say I won't be having any fuel starvation issues (as long as I keep gas in the tank)!
Total Time: 4.0 hrs.