If you are going super low on your 99+ GM Truck you might have ran into an issue. Your bedrail gets in the way causing you to smack your differential on this rail. Belltech has a solution to your problem.
A simple notch assembly that will give you the extra space you need. Note: if you purchase a Belltech C Notch kit for the 07+ GM Trucks this notch is included!
This notch will fit your 99-06,07-13 and 14+ GM Trucks.
Belltech Part Number: 6655
You can order by clicking here