OK- Did my first ground run today with the differential fuel pressure sensor attached to the 1/3 output side of the fuel pressure regulator (double banjo w/ carb jet press-fit) and the airbox <-> regulator line. What I saw was a steady 3.5 PSI up until wide-open throttle. Whenever I went to full throttle, fuel pressure dropped off to below 1 PSI. At the same time, the EGT on the 2/4 side spiked up 100 degF compared to the 1/3 side. When throttled back, the EGTs came back into alignment.
I'm at a loss for how to troubleshoot further. My fuel-flow tests a few weeks back were ~38 gph on either/both pumps.
