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
