car basically stock. I have heard the ngk tr55 are the best for the ls1. also what gap for the plugs

 

.055" - .060" is good for the LS1.

 

If you're staying stock and don't want to change the plugs every 25-30k miles then use the new Delco Iridiums.

 

The new Delco Iridiums are nice if you don't mind shelling out a little extra cash on plugs. NGK TR55s are great on a stock-ish, N/A setup.

Personally, I just use a new set of standard AC Delco. Never had an issue. IMO, there isn't really a "best" plug, just the right plug for the right application.

 

NGKs are cheap, available and work very well. They're pregapped in the .055-.06 range.

All of mine measured .057 out of the box, which was just fine with me.

Put down 346 with crush bent Y, LTs, and a stock catback + LS6 Intake.

 

GM's love AC Delco plugs. No need to spend extra money, when it was done right from the factory. Most come with platinum plugs anyway these days.

 

I run NGK TR55's in my C5, and the same in my old LS1 SS.

 

X2. I had Bosch +4 in mine for a while & it just was not "right". There is a Service Bulletin to use AC Delco Iridums & clsoe the gap to 0.040" if memory serves me correct ~ my 00 SS runs very good w/ these.