Hello,
What's the diff on the two plugs Tr5 & Tr55 ,, going into an 06 yukon 2006 4.8 engine.
Are they Platinum or Iridium,, i know to gap them at .040" went on Spark Plug .com and got confuzzed,, the stock # 2238 for the tr5 and 3951# for the tr55..
boomer1
What's the diff on the two plugs Tr5 & Tr55 ,, going into an 06 yukon 2006 4.8 engine.
Are they Platinum or Iridium,, i know to gap them at .040" went on Spark Plug .com and got confuzzed,, the stock # 2238 for the tr5 and 3951# for the tr55..
boomer1
