Spark plug Champion or AC DELCO

In my personal experience (99 suburban 6.2l 383) AC Delco spark plugs are the way to go

I have ACDelcos in my 2010.

I've changed them twice over the 120k or so that I've had the car and I didn't pay attention to what was in it when I bought it, but the person who owned the car before me had a receipt from Advance.

We changed that spark plug and the customer was happy with the magneto drop. That spark plug worked fine on a Champion spark plug bomb test.

Champions quiet redesign of their plugs to match Tempest made up my mind. It matters, and Champion is just trying to save face.

New Denso wires (these were the OEMs, cheaper to not pay ac delco mark up) and AC-Delco 41-962 plugs.

AC Delco/NGK.

IMHO, this is one of the times where the OEM stuff might be the best way to go, especially if your engine is otherwise stock. It's really common to see these trucks get well over 150,000 out of the original plugs and wires. They're kind of expensive but they just last so long it's worth it.

I bought six ac delco spark plugs from Rockauto and half were made in France and half were made in the US. There are very slight differences like the diameter of the electrode and how deep the plug is on the end that goes into the cylinder. Even one of the US plugs is different from the other two.

Side note, Champion spark plugs suck. Use them in lawn mowers.

When I got my S60 (2006, T5) the previous owner had some copper AC Delco plugs made to fit an 850 non turbo in it and I wondered why there was very slow engine response.

Champion is shit for cars. Leave it for mowers and weed eaters.