AC Delco 41-902 or 41-979 Plugs? What's the difference?

[wirlybird]

More Information for ACDELCO 41902

More Information for ACDELCO 41979

I would say the main difference is length if that particular spec is accurate. The heat range is supposed to be the same.

You have a Vortec? What are you running for plugs?

 

[Schurkey]

I think Schurkey is correct. The higher number the hotter.

The "new" part-numbering system deliberately does not provide clues to heat range.





Pick one, screw 'em in. Stop obsessing.

 

[wirlybird]

The "new" part-numbering system deliberately does not provide clues to heat range.





Pick one, screw 'em in. Stop obsessing.

I know it! Too much research.
Get this though. According to Delco -
The 902 fits both the 5.7 Tahoe and the 7.4 K3500
The 979 does not fit the 5.7 Tahoe even though it is the same dimensionally as the 902.
The 41-993 fits the 5.7 Tahoe but not the 7.4 K3500. Its reach is longer then the 902 but is ok for the 5.7 but not the 7.4.

I give up!! Someone tell me what they are using in their 7.4 Vortec and that is what I'll get!!!!!

 

[Frank Enstein]

What is the year, make, and model?

 

[wirlybird]

What is the year, make, and model?

1997 Chevy K3500 4X4 dually 7.4l Vortec.

 

[454cid]

On Delco's site it shows the insulator of one is slightly longer and wider but everything else is the same.
Some of the specs on Rock don't make much sense.

Yes, I think some of the information gets transcribed by people (or computer) that don't understand what they're looking at. Sometime I think metric and SAE measurements get mixed up.

I have an AC Delco plug, but I don't know what. I think I bought them locally. I do recall that the first time I bought plugs, the original factory installed part number was not available....like discontinued not available, not just out of stock. The last time I bought plugs, I bought some NGK copper plugs, but have not actually installed them yet. I've read that copper, while not lasting as long will work better in high mileage engines... I don't recall the reasoning behind it.

 

[Frank Enstein]

AC Delco's website sucks rotten eggs!

Any of these will work.

1997 CHEVROLET K3500 7.4L/454 Chevy big block Gen VI Spark Plugs Spark Plugs & Glow Plugs Ignitions & Electrical - Platinum Electrode Tip Material Parts & Accessories | Summit Racing

Find 1997 CHEVROLET K3500 7.4L/454 Chevy big block Gen VI Spark Plugs Platinum Electrode Tip Material and get Free Shipping on Orders Over $109 at Summit Racing!

www.summitracing.com

Double platinum plugs aren't needed when you have a distributor. They don't hurt anything but your wallet!

They DO help with a waste spark system though!

I would do the Autolite if you want a double platinum. They are a good plug at a good price.

I use the NGK GP platinum for my vehicles. I did use the Autolite double platinum plugs in my Yamaha and liked them.

Typical platinum plug life is often over 100,000 miles. Pick a brand, screw 'em in, and forget you ever saw them!

 

[wirlybird]

I have decided to go with the NGK Iridium IX TR55IX # 7164.
Too many questions on the Delco plugs.
Too many inconsistencies in specs on the 902 and the 979 when looking at different sites.

Trade the 993's in on the NGK's and hope all is well!