Ford F-250 460 P0171 and P0174 OBD2 Codes - How to Fix Emissions and Engine Light Issues

I'm experiencing P0171 and P0174 diagnostic trouble codes on my Ford F-250 460. The check engine light and emissions warning are both on. I've already replaced the factory-manufactured manifolds, changed the fuel filter, inspected and reconnected all spark plugs and wires. After these repairs, I took readings from the vehicle's sensors: load_pct at 77.3%, ECT at 88°F, short ft1 at 122.7°, long ft1 at 21.9°, short ft2 at 21.9°, long ft2 at 21.9°, RPM at 1440 — which correlates with the P0171 code. For P0174, load is 50.2%, ECT at 89°F, short ft1 at -0.8°, long ft1 at 22.7°, short ft2 at 1.6°, long ft2 at 24.2°, RPM at 1096, and VSS at 35 km/h. Despite these fixes, the codes persist. I'm looking for further troubleshooting steps to resolve this issue.