Best spark plugs?

[str8wkd]

I run AC's in my GM's and NGK's in my civic and raptor when it comes to regular services I OEM parts though just kind of a deal with me I guess might cost more but when you work on cars all the time you come to find out OEM parts usually last longer.

 

[boomer1]

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