The OEM chain is a budget O-ring chain with gold colored plates from one of the major makers (EK or RK, I think).
The 8400 lb strength is probably at least as strong, if not stronger than the OEM one.
I'm running a DID VM chain with a tensile strength of 9,760 lbs. DID's best chain, the ZVM, is rated at a tensile strength 10,400 lbs, and is the strongest one available, AFAIK. The ZVM is a popular choice for B12 riders and should take anything the B12 could ever throw at it, even with lots of horsepower mods.