1. Due to the original factory standard, replacement for 1500 2500 3500.
2. 12558177 is the reference part number, no need to worry about adaptation issue.
3. Pair of knock sensor grommets for gen 3 LS based engine, has in use.
4. Mount to the bottom of valley cover, directly replace the old or broken one.
5. Professional manufacturing, high precision, strong reliability, making sure safety use.

Specification:
Item Type: Knock Sensor Grommet
Material: Rubber
OE: 12558177
Fitment:
Replacement for
Replacement for
Replacement for
Replacement for
Replacement for Express
Replacement for 1500 2500 3500
Replacement for Trailblazer TBSS.1999-2006/2007 4.8L 5.3L 6.0L
Replacement for
Replacement for
Replacement for Trans Am
Replacement for
Replacement for LS1 LS2 LS6 5.7L 6.0L
Replacement for LS1 LQ4 LQ9 5.3 6.0 5.7L

packing list:
2 xKnock Sensor Grommet

Notice:
1. Please double check the part number of your item, matching information is for reference only.
2. If you are unsure of the item, please us before buying to avoid unnecessary return, thanks!