More realistically, your smog pump or water pump are/were no longer in perfect alignment, causing the chirp when the labeled portion of the belt went over the water pump pulley.

Many modern engine have some kind of pulley driven by the backside of the belt. Dayco makes millions of belts each year, if the printing caused issues, they'd have the common sense to change it.

 

For what this is worth...I had the same problem this past summer and went to my local NAPA dealer for advice. He came out and listened to it and said he could fix it in seconds. He went back into the store and returned with 1/2 handful of clay based cat litter. With the engine running he threw the litter directly at the intake side of the tensioner pulley and the noise stopped instantly and has not returned. He stated that it was an old trick he learned as a Ford mechanic. True story gentlemen.

 

Although dangerous with the engine running, I have done the following to find out where either a failing bearing, or squeal is coming from. Take a long handled screw driver and push it up against each accessory (in a location where if anything is to slip it will not be pulled into the front accessory drive) and put the opposite end to your ear. This amplifies the sound, and can often work to determine where the sound is coming from.

Are all of the front accessories intact? Smog pump is still there? Sometimes if the belt doesn't wrap far enough around a pulley, it will squeal/ slip.

No moisture is getting on the belt from anywhere that you can see?

 

^^^^ You can do the same with an automotive stethoscope; less than $10 at Harbor Freight. A LOT safer than a screwdriver.

 

When I don't drive the truck often, the power steering squeals upon startup and when I'm moving, but then it goes away. The more I drive the truck, the less I hear it. It don't like to sit...