2001 ford ranger 2.5l. Put the drill on the oil sprocket and found out the major oil leak was coming from the thermostat housing instead of the front main seal. Any ideas why? Completely rebuilt motor, had a remanufactured head that was shipped ready to install, cam and all.

There’s an oil plug that’s threaded onto the head right above the thermostat housing behind the black timing cover. Remanfactured head included the one in the back installed already, but not the one in the front.