I used Champion H-10's for a long time however, one time, (I think it was in the late '70's), I bought eight H-10's for my '53 Ford but, when I opened the boxes, five out of the eight plugs were missing electrodes...

I believe Champion had been sold to an off-shore company, and it didn't appear that the quality control unit was part of the sale...

After that, I switched to Autolite 216's and I've been using them, with no problems for over 30 years.