So many threads asking about how long it takes to change plugs on an LT1...here's new question:

How OFTEN do you change your plugs?

 

I think under normal driving condition, 80,000-100,000 miles

 

depends on the plugs.... I would go 30-60k on stockers, depending on driving habits. NGKs, I plan on changing every year just for something to do.... If you have stock manifolds, change them when you do headers, if not - then hold off as long as possible and purchase some AC delcos....

 

what's the best brand of spark plugs for stock LT1s?

 

I think it's dependent upon mileage. If the car was highway only, then you could add 10K to the intervals.
1st set- 50K
2nd set- 40K
3rd set- 30K
4th and beyond, 20K.
I'm basing this on 20 years of experience with high mileage SBCs. Yes, the plugs can live longer, but beyond 120K, it's likely that one or two cylinders will need the shortened interval to run 100%. I blame the valve seal design, they all burn some oil, even if there's no noticeable smoke.
Oh- and delcos all the way for LT1s. Some others seem to foul easily.
Later

 

AC Delco 41-943? or the rapid fire plug?