Hi. I'm thinking of replacing the plugs in the '04 intimidator I recently purchased.

I'm guessing that, being a chevy car, it came with Delco plugs. Are there other brands that would work better for a stock setup (with a homemade FWI as the only mod to the engine)?

Thanks.

 

It depends on what other mods you plan on doing...

Autolite Copper 605s on a stock L67 would work good, gapped to 0.050.

 

I would probably look at doing the u-bend removal and maybe the catalytic converter. I'm not a major tuner guy so for me to go and play in my daily driver and possibly break something..... well... I'm not there yet :-)

 

It came with NGK's. I just put in what ZZPerformance recommended: NGK Iridiums, 2 sizes colder, TR6-IX. Autolites are a better performance plug, but I drive too many miles for them. They are copper, and will burn up in 20,000 miles or less. They always have, they always will.
For racing, put in Autolites, but for driving, put in NGK's.

 

What would the colder plugs do? I'm hoping they would not impact any performance already in the engine. I read that it would help with knock but with a stock engine, there should not be any :-)

 

Are you planning on going to a smaller s/c pulley? If so, you will need colder plugs. If not, your plugs should be good for a gazillion miles.

 

At the moment, a smaller pulley is not in the cards. I understand that it requires the u-bend delete, high flow cat, cooler thermostat and a straight down pipe to help with the engine knock (that is, of course, if I didn't misread anything lol). If the pulley can be swapped without the other mods then sure... it's possible. I just figured that, with around 40000 miles on the engine, the plugs might need changing and was wondering which plugs would be best.

 

Autolite 605's work great and are long lasting. 104's need to be changed out more frequently, but are colder yet to avoid KR that might exist already.