Pistons

I used those KB107s in my 367. I used the KB ring-gap spec. I had overheat issues that I could not solve. The engine would also lock up every time I shut it off, for 10 to 15 minutes.
I took the engine apart and opened up the gaps to the next spec, and ran the hone thru her a couple of passes, and with no other changes, (except new file-fit rings) just like that, the overheat and the lock-up were solved.
Then I increased the minimum running temperature to 207*, and it still didn't overheat. Then I retarded the timing, still no overheat. Then I put a clutch on my fan, still no overheat. That was ~2002, Engine now has over 100,000 miles on it. With still the same sparkplugs. It used to be my DD.

Those hyper-eutectics are lightweight, strong enough for a 4-speed on the street, and mine revs to 7200 in a heartbeat, time and time again. I got nothing bad to say about the KB107s.

And yes, I would buy them again.