Bests & Worsts Reviews from Amazon

I bought these for my 2002 Silverado 5.3l. I had replaced the original plugs and wires with Bosch wires and plugs (Platinum +2) five years ago. I was not happy with the Bosch components but that's for another review. I'm glad to go back to OEM with these wires and the iridium plugs ACDelco 41-110 Professional Iridium Spark Plug, Pack of 1. The tricky part was figuring out which wire fit the truck since there are two listed (9748HH and 9748GG). The wire listings reference a number stamped on the coils but I wanted a way to tell without taking it off. After a good bit of research I found the difference based on part drawings in the service manual. The Melco coils (coils stamped 12558693) have a wire attachment point on the side and use 9748HH. This is why the wires are a bit longer. The Delphi coils (coils stamped 19005218) have a wire attachment point on the bottom and use 9748GG ACDelco 9748GG Spark Plug Wire Kit. They are a bit shorter. Another way to tell the coils apart is the attachment points. The Melco coils attach to the engine at the top and bottom where the Delphi coils attach on the sides. Look at the picture I've posted for more details.