As a general rule for an engine to live it needs to have a minimum 10 psi for every 1000 rpms. Most stock engines will have 15-30 psi at idle hot and 30-60 psi at 2500 rpms hot. Also a decent test, warm engine at idle turn the key off. If the oil pressure stays above zero for 2-3 or more seconds there is no major bearing or oil pump clearance problems. If the car has an oil light or an electric gauge turn the key back to run after shutdown as fast as possible. The light should stay out long enough to see it out. Electric gauge see above though electric gauges maybe too slow to give accurate results. Factory Ford gauges are too slow for sure.