Aeroflow now offer -4AN water cross-over adapter˝s and allow coolant to be pulled away from hot spots in your cylinder heads to suit LS1, LS6, LS2, LS7, LM7, LQ9 engines. Comes complete with O-ring and mounting bolt ready to install and are sold separately. Aeroflow water cross over adapters are especially needed for turbocharged or supercharged street driven / endurance applications and allow many ways to plumb a simple cross-over line or header tank to allowing the engine to run more efficient while allowing the coolant system to hold more coolant. Installing these water cross-over adapters in all 4 corners of the engine have been proven to decrease detonation in number 7 & 8 cylinders especially and are a great improvement over the standard steam vent plumbing.