Chain tensile ratings.

This should probably be listed under tech but I'd rather ask Vitards opinions on this.
I help out a sister team on KX100's. Chain/sprockets have been an issue in the wear dept.
So I REFUSE to put Alum rears on the bikes. But, The sprockets are holding up as steel should. the chains, which I don't remember what their DAD put on shows a half a link wear at the rear-direct across from the axle. Mind you, these little bikes run 420's. The sprockets, show no wear. What do you guys use in the way of a higher tensile strength. Blah , Blah, Blah chains come in a nice box with a prominent name, but I need something from the US or JAPAN. Not one of the Prominent ones that are packed as a name brand but actually made in China,Taiwan, Thailand etc. Kind like the Wiseco cranks Vs the Hot Rod cranks.

Thanks guys