These tanks were specifically made for your GM truck.
They measure approximately 11" from outlet to cap flange.
The unit has a 3/4" threaded outlet that accepts a 3/4" x 1" fitting on the bottom.
So it fits the factory coolant hose that connects to the bottom of the factory overflow tank.
The side drain/port on the tank fits the factory overflow hose.


$131
Price includes: tank, mounting bracket, 3/4" brass fitting, 1/2" brass fitting.
You'll need to pick up a standard 16lb radiator cap.