1999, LS1, FRC....using NGK,TR6.....Now my engine is far from stock, What spark plug should I use?....

 

41-162 (superseded 41-110) is the current gm recommendation.

 

what's your reasoning for wanting to change?... far from stock, so what's done?... it's hard for anyone to give a recommendation without any information

 

Cam heads, intake, full exhaust..

 

Blast if I know, I run a stock engine and stock GM plugs. If you ever need a non functional, wise guy answer, that's more my deal.

with a non stock engine, I don't have that skillset, I would have to ask the person who modified the engine,.

Or find someone with the info, perhaps ask at a local speed shop with an engine builder. a few guys posting here would know, if you described what you have.

I would think the brand or type or plug construction is not important, given the quality of todays ignition systems. But I have read that ignition temps are a major consideration in creating efficiency , and thus maximum power when air flow, fuel density and all the other nessisary elements of concern are factored into the problem.

I was mostly responding to the suggestion of going with stock plugs in a non stock engine. Not that I am offering better , or even contradicting info, because I don't know. it just seems logical to double check fitting factory spec parts on an engine that is now outside of the factory spec design. I fairness to the poster offering the stock parts number, I don't even know if what I consider logical thought applies her, so no offense , or correction, intended..

 

so you have probably added at least 100rwhp more than what it was when stock, one step colder on the plugs (which the tr6 is) is fine... what are they gapped at and why do you want to switch?

 

The gap is 40.....just time for new plugs...

 

I am putting in ACDelco 41-162 plugs this weekend with ACDelco red wires......after 16 years it is now time no matter what mileage...just sayin