emarkay

Bone Stock LS1 with 80K miles and need to do plugs.

"PARTS INFORMATION:
A new spark plug has been released for use in the above vehicles. The new spark plug has an
Iridium tip instead of the current Platinum tip. Due to the different tip design, the gap of the
spark plug has also changed. The new spark plug, ACDelco Part Number 41-985 (12571164), is
gapped to 1.01mm (0.040 inches) when the spark plug is made. The spark plug gap is set during
manufacturing and should not be changed to the gap required with the Platinum plug, or damage
to the spark plug may result"

Of course this is old news (2003), but I find no detailed mention of it here.
http://www.acdelcotechconnect.com/pd..._03D-J-171.pdf

Otherwise should I just stick with TR-5s's or what??

Marc '99T/A

iTrader: (22)

I just stayed with the TR-55's when I did mine this weekend. They worked fine for me in the past, so I figured why change what ain't broken? Just my $.02.

oange ss

iTrader: (50)

I had Denso Iridiums in my car from the factory, when I replaced them with TR55's the gap ranged from .056-.064

BULLET99Z28

iTrader: (9)

I to replaced platinum with the Gm Iridium, good so far, I gapped at .050. Correct me if wrong, but Iridium is fine as long as you are N/A or no N2O.

oange ss

iTrader: (50)

correct

Lee Mike

What is the best precedure to change the number 8 spark plug on a 1999 firebird firehawk?

Marc '99T/A

iTrader: (22)

From the bottom.

02SSLE

iTrader: (26)

Jack the car up and go threw bottom. Very easy for me. The easiest plug.