I went to the dyno tuning shop and got my car tuned after I increased the fuel pressure from 37 psi to 50 psi. Max injector flow has gone from 29.0 lbs/hr to 33.7 lbs/hr.
The injector % duty cycle at 7200 rpm was 89% with 37 psi, now the % duty cycle at 7200 rpm is 72% with 50 psi.
Difference report for the VE table, left side graph is 50 psi & right side graph is 37 psi.
The engine made a little bit more hp at the top with 1 degree more advance at 6500 - 7500 rpm as shown in the difference report for the Ignition table, left side graph is 50 psi & right side graph is 37 psi.
The dyno graph shows max wheel torque unchanged at 206.5 ft-lbs while max wheel hp increased from 232.8 hp @ 6600 rpm to 238.1 hp @ 7100 rpm.
Thank you Dave (montauk) for asking me why I was running with the fuel pressure so low. From the resulting discussion on this thread and observations made while working on my tune, I have learned a bunch and gotten a better performing engine as a result.