Ironic to start the gen 2 troubleshooting sub with a question about stopping, but whatever.

My front brakes started making noise the week before MOD. As in, it sounded like the feeler was making contact while moving (read: not touching the brakes). Short on time, I simply replaced the pads.
I know, I know. And, for some reason, I always hear Ryan's voice in my head reminding me I need to get the rotors checked and turned if I'm gonna do it right. But "doing it right," to me anyway, means upgrading to braided lines, speed bleeders, drilled rotors, and manual hubs. (I'd also like to replace the UCA bushings, died-within-a-year Mevotech ball UBJs, and maybe lay down a fresh coat of paint while I'm in there, but I digress.)
Within 24 hours, the front brakes were making the exact same noise. That shrill, hissing, metal-on-metal sound that makes even the finest machine feel like a complete piece of shit. Again, I digress.
Yesterday morning, I replaced all four guide bolts on the front calipers with new units from NAPA. I removed the pads, flushed the bolt holes with WD40 until it ran clear, then flushed with brake cleaner until that ran clean. I let things air dry before chasing the threads with the new bolts—all the way and back out twice—before reinstalling the pads with new clips, and greasing the new bolts with the highly recommended Syl-GLide, silicone brake parts lubricant. I applied a thin coat of this to the back of the pads, too.
The brakes STILL make noise while driving. WTF?Fezzik stops just fine, but I notice when I squeeze the pedal (like when you have to stop shorter than expected—not even what I'd call threshold braking), the front brakes make a grumbling, almost crunchy sound.
I'm thinking, considering the PO put 160k+ on the original timing belt—and rounded off the upper guide bolt head on the driver's side caliper, AND removed the CEL & SRS lights before selling the truck—it's also likely these are the original rotors. I don't have the right kind of mic/calipers to check rotor thickness correctly, and I'd rather replace the alternator next, but I'm hoping someone here will be able to say,
"Oh yeah. Without a doubt. You need new rotors."Thanks in advance.