72T huh? I'll have to see what's available here for a possible project with a pocket bike engine. Thanks for the informative video!
You asked for suggestions. KMC X9e EPT chain is about three times the price of most SRAM chains, but it is intended for high output mid drive electric bikes, so that could be the answer to your chain troubles.
Also you
need to get plugs or preferably big fat metal bmx bar end caps to cover your handlebar ends.