JRSSTOY

So I just bought a 03 Z06 with no mods and about 37 k miles, Im trying to some maintenance on it and I got started with the spark plugs, after several debates with my buddys and previous experiences I decided to go with the standard NGK TR5, auto parts store stated they should be gapped at .40, NGK website states the same, however after doing a search on this forum I found most members gap them at .55. I checked my new spark plugs and they are set at .40 .Can any one tell me the right gap PLEASE?

JRSSTOY

Someone gotta know the answer to this ???

JRSSTOY

Whats the difference between the NGK TR5(2238) and the TR55 (3951) they are both v power copper plugs right? cause i remember using the TR 55 on my LS1 SS but now i have the TR5 that I got from Kraegen/O reilly's is this the same plug with a different preset gap?

02*C5

iTrader: (1)

For the TR55/TR5 .55. There is no difference between the plugs one is just gaped smaller from factory. I have used both gaped them at .55 in my N/A application with no issues. Good luck.

NoTractionLS1

.55 they should all be gaped where they need to be but it never hurts to check!