[Todd Gross]

I had one customers' engine that I tore down for a freshen up only to find multiple spiro loc failures. To the point of serious cylinder wall and piston damage. After digging for info I found out the previous assembler purchased his spiro locs in bulk from McMaster Carr. Needless to say the quality control ( heat treat ) may not be up to the quality of that of a Performance Piston company. I installed JE locks and 2 seasons later on freshen up, no more failures on a 700" .
I am not suggesting that that toolmakeron's engine has McMaster stuff in it, just sharing an experience*