Is An FX-8370 Viable For Emulation?

It depends on the game, overall you won't get the same performance you'd get with a decent CPU but it's a nice performance boost overall. Just overclock to a sweet spot and stay there. Mine is 4.6GHz.

TSX Instruction Set is a plus, Intel architecture over AMD due to the CCX latency issue, and lots of cores like i7 8700K or i9 9900K (but not too many like Threadripper).