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Ive noticed a few guys running NGK plugs in their Vettes now a days. When I was younger, I was told nothing but AC Delco should be in a GM. What plug is suggested and why for a stock C5? Not sure if I should go NGK or Delco.
Just ordered these from the guys over at CULTRAG Performance - they were super helpful and got them to me in 2 days. I got the wires from them too - if you need more info - just PM me.
OEM spark plug is AC Delco 41-110 Iridium, pre-gapped at .040
11 ft. lbs torque, and a small dab of anti-seize on the threads.
GM red plug wires are recommended. Dielectric grease can be used on the insulator portion of the plug to make the new plug wires easier to remove.
Do a search on "changing spark plugs" on the forum. There are several write ups with tips on tools, and moving/removing certain parts to gain access to the plugs.
OEM spark plug is AC Delco 41-110 Iridium, pre-gapped at .040
11 ft. lbs torque, and a small dab of anti-seize on the threads.
GM red plug wires are recommended. Dielectric grease can be used on the insulator portion of the plug to make the new plug wires easier to remove.
Do a search on "changing spark plugs" on the forum. There are several write ups with tips on tools, and moving/removing certain parts to gain access to the plugs.
Red wires? All the ones Ive seen are black. happen to have a part number?
Sorry if I'm a little late and a bit **** with this reply...
The stock C5 LS1/LS6 spark plug was the ACDelco double platinum 41-962. When the LS2 came out in the C6 the factory switched to the ACDelco Iridium 41-985 plug. This plug has been replaced/superseded by the ACDelco 41-110 plug. Now yes the new Iridium plugs can be back fitted into the LS1/LS6 engines - and many have done so without any issues.
If you are running a higher horsepower n/a engine with say +375 rwhp and most definitely above 400 rwhp, it would be wise to go with a one heat range colder spark plug just to be on the safe side.
Mike Morris fitted my rebuilt, modified and tuned 5.7L engine in my car with NGK TR6 plugs. It's been about two years and 3.5K miles now so when she comes out of hibernation this coming Spring, I will install some fresh TR6IX plugs. I like these 0.6mm center electrode Iridium NGK plugs and they have run great in other modified engines that I have had as well.
OEM spark plug is AC Delco 41-110 Iridium, pre-gapped at .040
11 ft. lbs torque, and a small dab of anti-seize on the threads.
GM red plug wires are recommended. Dielectric grease can be used on the insulator portion of the plug to make the new plug wires easier to remove.
Do a search on "changing spark plugs" on the forum. There are several write ups with tips on tools, and moving/removing certain parts to gain access to the plugs.
Delco also makes a platinum plug for the C5 ($2 difference in price) but I would use the iridium ones shown above. We've found that platinum doesn't run as well over time compared to iridium.
Just ordered these from the guys over at CULTRAG Performance - they were super helpful and got them to me in 2 days. I got the wires from them too - if you need more info - just PM me.
Just picked up 8 of the iridiums at Advance - in stock on the shelf.
Last edited by Ed Ramberger; Nov 10, 2017 at 07:58 PM.
The smaller the contact, the lower the voltage necessary to bridge the gap. Nickle alloy -- 'copper' core plugs -- are just under .1" in diameter, platinum about .04", and some Iridiums as small as .025"
I needed a dial caliper to measure the gaps on my original Delcos -- .075"!
What spark plug
The AC plugs are very good.
