Well,not sure about AC Delco belts. This is what I can tell you about the cheap belts though. The belt on my 97 was getting bad, so I got a cheap belt from AutoZone. Belt was squeezing after no time at all. The maintainace supervisor on the oil rig I was working on told me, to go get a Gates belt. I said yes, but it's 3 times the price. He said yeah I know, but it's worth the money, and it won't squeal. So I did, and that was 7 or 8 years ago. The belt still looks grate after all of this time. Still no squeak at all. Gate is made from better material than the cheap belts are.