Rpms look fine, Fuel pressure seems fine, too

note: You know that you may have already "cured" a low power complaint, with new fuel lines and new filters and new fuel check valves; because you didn't have any fuel pressure reading, Beforehand, to compare to.

You haven't mentioned "How long" does it actually take to start. (5 seconds cranking, 10 seconds or 30 seconds)

Also, was/is the hard starting, just in the mornings? or EACH time a person cranks the engine? {if problem was only each Morning, then You may want to inspect the fuel return check valve, also}

If it does take a long 30 seconds, of cranking; have you removed Air-to-Air tube and just tried a very quick squirt of ether, just to see how quickly it might start running?(might be a clue, to worn injectors, when those engine start very quickly with just a touch of ether, BUT normally we have tested and readjusted every adjustment and any another possibilities, before condemning a set of injectors) = basically only when you total believe you have everything "perfect" and it still takes 20-30 seconds of cranking OR a quick shot of ether(to be able to start quickly), do we finally commit to installing a complete set of injectors.

How do those clear fuel hoses "look" when you first start/crank the engine? Big bubbles anywhere?

note: there are areas, that we having even talked about yet, such as injector timing, valve adjustments, injector synchronization, governor inspection, "Full Load" setting, testing air/fuel ratio control., etc.