Originally Posted by CliftonGK1

I've been using PC971 chains on my commuter/brevet bike for the past year without any problems.
I weigh 250 pounds, ride tons of hills, and have never broken a chain even while standing and stomping the pedals to get up some of the 20% grades around here.

If you're peeling the side plates off, it sounds like you might be cross-chaining and putting a lot of unnecessary sideways stress on the chain.