Spark Plug Replacement

[Buckeyemurph]

I have a 2002 Silverado 2500HD, 8.1 engine, Allison Trans. with 120,000 miles. Running good but I use it to pull my heavy fifth wheel RV so I am considering changing the original spark plugs and wires. Am I wasting my money and which plugs and wires should I use? Thanks for the help.

[Black02Silverado]

I would go back with the AC Delco's that you pull out. I'm sure there is an updated version.  Not sure what it would be but someone will chime in. 

 

As for the wires.  No need to change unless you want too. 

 

Here is another thread on this subject.  

[Colossus]

On the 8.1 assuming it came with regular copper plugs you should be changing the plugs every 40,000 miles or so and wires every 75,000-100,000 miles.  And like above, stick to the AC/Delco

[Supreme Pizza]

Change the plugs if they are the factory originals.

Call the dealer and ask them for the recommended plug part number. 

"Plug" that part number into Amazon, and sort by price. 

 

You can usually get 8 OEM plugs for around 50% of the MSRP. 

 

I can usually find 8 iridiums for around $30 with free 2 day shipping. 

 

Be careful buying them on eBay, as there are many counterfeit plugs on that site. 

[diyer2]

Or check here. 

AC Delco rebate. https://www.acdelco.com/offers-promotions.html