Spark Plug Wires.

[iLikeEggs]

AC Delco is usually a good bet!

 

[Wake]

I think the "9" prefix indicates 'replacement' or aftermarket. The 748 plug wires come with UU, RR, WW, etc. etc. suffixes, most all are available with the "9" prefix and are usually lower priced.

I'm trying to figure out if the suffix (UU, RR, etc.) is only the color or if it indicates something else. You'll find both referenced for the 2009 6.2 motor.

The two different part numbers are likely due to two different coils used. One wire set should have shorter wires than the other. I had that problem when I changed them on my Escalade. One coil design is bigger than the other and both designs were used depending on when the truck was built. Of course I required the more expensive longer wires after finding the cheaper ones were about an inch too short.