New Dorman coolant crossover tube with rear block offs.  Tube attaches to the front of each cylinder head to transfer coolant from 1 side to the other.  For use with 07-13 6.0L/6.2L truck LS engines or intake mounted supercharger swaps. This is the "straight up" version of the neck compared to the 99-07 "angled" truck tubes.  Stock replacement for the following:

07-13 6.0L/6.2L Sierra/Silverado