I for one would be surprised if an OEM belt were NOT Kevlar now (barring NOS parts), the material moved to be used in most belts around '98-'00. If you look at belt change intervals around that time most of them doubled at some point, it's because of the kevlar.
That is separate of course from the Gates racing belt line (blue), which I haven't been too big on either. they simply don't last any better than the OEM Kevlar belt. Most of my experience is with Fords though. Ford went from 60K change intervals to 120K when they began to use Kevlar in their OEM belts.