Spark plug Champion or Denso

Denso always.

I also went with the IKBH20TTs. I noticed my mpg was better after doing so, and the truck seemed to idle and drive smoother.

I ended up going with the Denso IKBH20TT because I couldn’t find any FK20HBR8 at a reasonable price and availability.

I used champion spark plugs.. no problems here

The spark plug on the right is 10000% original because it's still working even though it's over 5 years old and has more than 87,000 km on it. The new ones show a little over 5 kilo-ohms, which matches Denso's specification. The old ones show a bit over 3.5 kilo-ohms due to wear.

NGK/Denso are good plugs for my car I used IK20 Denso plugs as they are iridium plugs which is what you want as they last much longer and are better quality

I've been running Denso Iridium on 7 Saabs for years.. both 9.3 V6 and 9.5 2.3l... never an issue on any after 100s of thousand of miles.

I replaced the plugs with DENSO 5358 roughly 10K miles ago.

BEWARE O’REILLY’S AUTO PARTS CHAMPION SPARK PLUGS ARE WEAK AND BREAK AT THREADS AFTER HAND TIGHTENING AND THEN TIGHTENING NOT EVEN A QUARTER INCH OF A TURN, WAY BEFORE THE TORQUE SPEC AND THEY TWIST RIGHT OFF N BREAK.

Like everyone has mentioned just go back with an ac delco plug. I ran champions and had Mis fires, none of them were gapped right out of the box.