[Scott5000]

Thinking about upgrading the plugs since they look so easy to get at. I heard the stock plugs are AC-DELCO irridiums. Does anyone know if these use a tapered gnd electrode like the NGK TR-55IXs? I put a set of the NGK irridiums in my 5.3L Avalanche and the motor seemed to respond well to them and gained 1 more mpg on average. Or I may just go with the TR-55s since most people seem to have good luck with those.

05 GTO MN6 (Blk/Blk)
504 miles on the clock

 

[KERLS04]

I Wouldnt Mess With Them The People Who Did My Car Said That The Ls1 & Ls6 Have Great Plug And Plug Wires. There Not Worth Replacing Unless You Have A Lot Of Miles If You Do Your Just Wasting Money Unless You Are Going For Looks