Little update:
Hooked up my scanner (Autotap with the full Ford package) and read out some values. The long and short term fuel trims are not unreasonable. The shorts are near 0% and the longs for both banks hovering around -5%. In fact this is pretty good. The front O2 sensors show good rich/lean crosses at idle so it's not simply sitting rich. MAF looks pretty steady and stable as well.
One thing I did notice was that my scanner showed the fuel pressure at 54PSI at idle and at 2000RPM. My Ford shop manual says the normal engine-running range is 35-50PSI.
The fuel trims being normal-looking don't seem to jive with the fuel pressure being that high. Thoughts?