Gates Poly Chain was a new belt tooth profile that came out many years ago. Unlike the standard timing belt profiles used in other applications that were more flat and shallower, the Poly Chain profile was almost a half round lug profile that would stick deeper into a pulley providing "chain" like load bearing capabilities unlike other timing belt profiles.
So today Poly Chain is more a type of profile than a composition make up of the belt. Gates did use polyester fiber for reinforcement which was new way back when as well. Now the carbon fiber, Kevlar, Aremid fiber etc, is the new high strength reinforcement that most all companies use in their high torque belt applications.
So I assume it would be safe to say that Proctor just has the Gates belt, whereas I bought the Falcon...just to be simple?

I've got probably around 3000 miles on my Falcon, going through all the motor mods, with around 123 for hp/tq & no problems yet.
In the process of going 117ci or 124ci right now, just trying to make the decision on the crank - make it a stroker or not.
So we'll see how the belt takes that abuse in a month or so.
