What would you change with my baffling? Was only in the upper 70's.
Hey rm,
I wasn't suggesting that your baffling is inadequate. That temp. should be OK as well.
I would say that the metal came from around the plug thread.
Thinking about it some more, it looks to me like a result of detonation or too high compression ratio. Could be a result of incorrect pipe length??
Most likely your set up as you have had 2 that ended the same way.
Cheers