I have a 91 GT that recently developed this loud annoying sound on startup. I have searched the net and some people have mentioned a Camshaft Position Sensor...but none specifically for a foxbody 5.0. The sound is similar to videos posted on the CPS, however I have uploaded 3 videos in an effort to solve this quick since it is related to the engine and it is my daily driver.
The noise is definitely not pulley or belt related as it is coming from the driver side of the engine near the firewall. Descriptions of videos will pertain to the stage.
Here's to hoping its not something major...