SPW8100 - UltraPower 8.1L Magnum Spark Plug Wires

SPW8100 - UltraPower 8.1L Magnum Spark Plug Wires

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Verified to have been manufactured in the USA


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Most orders are shipped within 24 hours from the order date. Orders placed on the weekend or after cutoff on Friday, and orders placed on select holidays are processed on the next business day. Please see our shipping terms for more information.

Part# SPW8100 - UltraPower 8.1L Magnum Workhorse Spark Plug Wires


UltraPower Magnum Spark Plug Wires are patent protected because of the unique method of producing these wires which have extremely low resistance while maintaining very high noise suppression. The benefit of this invention is that full electrical energy from the ignition source is transmitted to the spark plug. The end result of the application of this method is increased horsepower, torque, fuel economy and a smoother running engine.


  • Patented Solid Stainless Steel Core Spark Plug Wires with RF Eliminator
  • The technology in these wires comes straight from Nascar and is not available on the open market. They are made out of a patented zero OHM, solid core stainless steel wire wrapped by silver plated copper conductor wire and are outfitted with an RFI eliminator collar that guarantees no interference with radios.
  • These wires must be installed with GM factory heat shields which may be reused off your old wires.
  • High temperature silicone boots, 8mm jacket with fiberglass-reinforced braid that resists temperatures up to 500°F.
  • Increase power to the spark plug up to 400% over stock!
  • Adds up to 15HP on Big Block GM engines.
  • True Life-Time Lasting Wires, Life-Time Warranty!


  • Workhorse chassis with 8.1L (2001-2011)
  • Workhorse chassis with 6.0L (2004-2006)
  • All GM vehicles with 8.1L (Silverado, Sierra, Avalanche, Yukon XL)
  • Industrial applications with 8.1L (Generators, Forklifts, Pumps, Compressors, etc)

Comparison and installation video by one of our customers:

I have 56,000 miles on my 2002 W22 chassis for a 2003 Newmar Mountain Aire 37 ft gas motorhome with the 8.1 L Vortec. It runs well and I have the original spark plugs in it but have a set of the 41-101 iridium plugs that I plan to install. My question - what is he benefit to installing your SPW8100 Magnum plug wires with the new iridium plugs? Can I expect improved performance? The engine is bone stock.
( Jerry Eck, 06/24/2021 )
The Magnum wires improve the spark energy to the spark plug because they have no resistance in the wire. They would also last the lifetime of the vehicle, so no need to ever change again. ( Support )
I am about to order the SPW8100 - UltraPower 8.1L Magnum Spark Plug Wires and noticed the caveat that the "wires must be installed with GM factory heat shields which may be reused off your old wires".

If any of the existing heat shields are damaged or such as not to be able to be used again, do you have them available or at least know the part number so I can get them from a local Chevrolet or GMC dealership?
( Jeff, 01/29/2021 )
If you need a replacement heat shield, the part # is 19329681. We do have them in stock if your local GM dealer does not: https://www.ultrarvproducts.com/19329681-Spark-Plug-Wire-Shield ( Support )
How do I decide if one of these wires has gone bad? I’m having an issue with my 8.1 vortex misfiring slightly loosing power going up slight grade under power. Have replaced coils today but still have some misfireing after about 2 hours of driving. Replaced with your wires and new iridium plugs about 5000 miles ago. Motor home is throwing no codes. No check engine light. Have run with Obd2 connected and no codes. ( Gary Delpiano, 10/25/2020 )
You will need to pull the wires and inspect for any heat damage. Check resistance on each wire, they should be at or near 0 ohms and if you have one that is significantly higher than the rest that would indicate a bad wire. ( Support )
Is this price for a set of (8) or per wire? ( Tim, 08/13/2020 )
The website price is for a set of 8  ( Support )
i have an 8.1L in a 2002 Workhorse P32 Winnebago Brave. A few years ago the engine starting making popping sounds when warm and under load, like when going uphill. I had the fuel filter replaced and it didn't help. Then i ordered the Magnum plug wires and had them installed by the local Chevy truck garage a year or 2 ago. This seemed to help for a while but now the popping is back. My question is if you know of an experienced 8.1L Vortec garage or mechanic in the mid Atlantic states or Ohio that can get to the root of this. I live in Roanoke VA but can travel to find a good mechanic. Thanks! ( Don Reed, 09/16/2019 )
The nearest Authorized Workhorse Dealer that we know of with good experience is Larry's Auto Clinic in Myrtle Beach, SC: https://www.larrysautoclinicmb.com/ ( Support )
What temperature are they rated for? What is covered under the warranty? ( Jerry, 07/25/2019 )
The boots themselves are rated to 500*F continuous. Our Extreme wire set is rated to 1000*F continuous. The warranty covers any issues with the wires or failure due to heat, excluding direct damage from leaking exhaust. ( Support )
I am currently burning premium gas going to change plugs to the AC Delco 41-101, what would be a better choice of gap? Plus what is the difference SPW8100 wires and the SPWEX8100 besides $? ( Ray Benson, 06/10/2019 )


    You can run the standard .060 Gap on the plugs that would work great. The difference between the SPW8100 and the SPWEX8100 are the EX have heat socks on the wires.

( Support )
how do you remove the heat shield off the wire
( joey, 10/18/2018 )
They just slide off. If the wire has gotten really hot it's possible that the rubber boot has melted to the inside of the heat shield which would then require replacement. ( Support )
HI i have a 2001 Silverado HD 4x4 with the 8.1 and Allison tranny I was wondering you folks suggest the ACDELCO 101 plugs from what i see in the truck forums they all suggest the 993 now that they stopped making the 992 ACdelco plugs, i just purchased your SPW8100 - UltraPower 8.1L Magnum Spark Plug Wires, ....so why do you suggest the acdelco 101. is there much difference?...thank you so much. ( Darrel, 04/15/2018 )
The 41-101 is the best suitable iridium spark plug to replace the 41-993 platinum. We have been using the 41-101 for many years now with no issues. ( Support )
I'm getting ready to install these wires. What would the plug gap for AC Delco 41-101 be? I've read 45 as well as 60.

( Jack Blacklock, 02/24/2018 )
The 41-101 come pre gapped at .060. You can adjust them to .045 for a little better performance but it is not required.  ( Support )

How hard are these to change on a Motor Home? What type of connection is on the opposite end of the spark plug end?

( Jim Smola, 01/08/2016 )


We have found that it is easiest to change the spark plug wires from inside the wheel well. Just turn the wheel the direction you are working on to full stop so you can get in there and once completed with the one side do the same on the other. The other end of the spark plug wire (the coil side) is just a push on fitting like the spark plug end.

( Support )

What do I do if one of these wires ever has a failure?

( Lyle, 03/14/2015 )

You would just call us, we will give you a RMA number for the wire for you to send back and we will send one out right away at no charge.

( Support )

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WARNING: Products may contain one or more chemicals known in the State of California to cause cancer and/or birth defects or other reproductive harm. For more information, visit www.P65Warnings.ca.gov

VIN Verification Service Item

This product allows for a VIN verification service.

  • This is a service that we provide free of charge when a part is purchased.
  • When you provide your VIN below we will personally verify your part selection by your VIN before shipment of your order.
  • This helps ensure that this is the correct part for your vehicle.
  • This is not an automatic VIN check, it is done by a parts specialist once order is placed.
  • We can only VIN verify vehicles back to model year 1996, if older we can help but can't guarantee fitment.
  • If you would like to have your part selection verified before purchase please call or email us.

Shipping Insurance Notice

NOTICE: For orders outside of United States

If you are placing an order to ship outside the United States, Shipping Insurance will be required and added automatically at checkout.


  • Views: 83386
  • Brand: UltraPower
  • Product Code: SPW8100
  • Availability: 31
  • $202.49
  • $149.99

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