This is probably the problem as you've stated how careful you were. I'm ocd too22761722 GM. Got them off Amazon though, has me wondering .
about stuff...
Been proven time and time again that alot of branded parts are counterfeit on Amazon.
I bet if you bought them local or on rockauto, you'd get ones that are packaged
"similar" but not exact .. and not the exact parts either...
Sorry for the bad luck. Don't trust amazon or ebay on name branded (mfr) named
stuff. Get it local ... even though the prices are vastly different