Correct. As I saw it one of the major stresses on any of our primary pumps is from the dual role it must play having to both pull vacuum and push positive pressures. You then are adding a water fuel separating filter that is creating that much more resistance. By removing half of that it goes a long way to increasing pump longevity. This setup is good as long as you have a high pressure pump setup that can supply the needed flow rate. But if I was going to run dual stock Bosh pumps I would still run them in parallel. BTW 2 pumps to reach a flow capacity compared to one is will always have more advantages. My issue was my fuel needs are right at the edge of what 2 SD pumps can hold and when I move up they will no longer hold the line. I was also trying to create from the ground up a system that would deal with all the various weakness of the 7.3 system.
So if you wanted to go with a great system for injectors up to 200% nozzles you could purchase 2 new Bosh Super duty pumps for $200 total ( thats for both). That would given you the fuel you need plus redundancy should a pump go out. I would make sure to wire both pumps into separate relays and wiring so you keep your isolated redundancy. I would go into the back inspection ports in the rear of the heads with -6an hose then come out the front standard ports to the regulator with -4an hose. From the reg back to the tank with -6an hose. You can add a trans cooler to cool the fuel in that return line should you so choose. ( I would) Do not use Ts or street 90 fittings. Use only Ys and long radius hose ends for needed turns where every possible. I prefer Donaldson filters over all others other than the DAHL. Donaldson P551000 for the water fuel sep @ 10 mic absolute and P551311 for the Final filter @ 2 mic absolute. I like to use Baldwin FB1311 Filter Bases. A single -6an is fine up to the Y to go into the heads and will handle way more flow @ pressure rate than you will ever need.
You can also always look into some of the prefab kits our vendors offer. They are all very good quality.
