Square vs round coil packs

Airtime · January 28, 2020

Hi all, I have an o2 Silverado with the 5.3 and a 03 trailblazer also with the 5.3. I use the trailblazer as parts for my truck. The 02 has square ignition coils and the other has round ones. Are they interchangeable and if so is one better. My 02 is aging with 220k on it and I'm starting to switch more and more over from the 03 with 150k. Just looking to keep the truck going as long as I can. I swore I would make it 20 years when I drove it off the lot in 02 but I'm not sure if its going to make it. Any ideas would be appreciated,

Thanks

CamGTP · January 28, 2020

If you have no issues with the coils now, don't change them.

I believe there are ignition dwell settings that are going to be different between the two types of coil packs.

CapitalTruck · January 28, 2020

I know they used to provide both options for replacement. I doubt they would have done that if it wasnt necessary.

tlaw91 · February 2, 2020

Ignition coils never go bad on those. Ever.

I mean like ever.

Hope this helps

-Friendly neighborhood GM tech

Sent from my iPhone using Tapatalk

Gagliano7 · February 3, 2020

Interchangeable Everyone swears the round ones are more powerful but i have both coil types and there is no difference in my opinion.

High Country 6.2L/8 · March 11, 2021

On 1/27/2020 at 9:01 PM, Airtime said:

Hi all, I have an o2 Silverado with the 5.3 and a 03 trailblazer also with the 5.3. I use the trailblazer as parts for my truck. The 02 has square ignition coils and the other has round ones. Are they interchangeable and if so is one better. My 02 is aging with 220k on it and I'm starting to switch more and more over from the 03 with 150k. Just looking to keep the truck going as long as I can. I swore I would make it 20 years when I drove it off the lot in 02 but I'm not sure if its going to make it. Any ideas would be appreciated,

Thanks

Is it a waste of money to upgrade to performance coil packs and wires? Have a 2017 Silverado with 6.2L. Heard some negative reviews about throwing misfire codes. I'm sitting on the fench because of the $1000 my wallet will be lighter as well. Sure they look great but want more than looks