Spark plug Motorcraft 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.

I however replaced mine with motorcraft and do not have pinging anymore but still run 91 octane as 93 isn’t common in socal.

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.

Acdelco plugs....Never had problems with either

On any of the gas trucks with the "modular" engine family (4.2 V-6 and 4.6/5.4 V-8) it seems like if you use anything other than Motorcraft spark plugs and coil packs, the engine won't run right at all, no matter the brand.

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.

My 6.0 never ran right unless I used AC Delco. And specifically whatever the current equivalent part number is to what the manual says.

I initially got the P0101 code and did the obvious - replaced the MAF sensor. No change, same codes. Goodbye $100.