Engine swaps almost never line the radiator inlet up with where the factory put the outlet. A neck that rotates a full turn at a 30 degree angle lets you point the hose wherever the radiator actually is, instead of buying a fabricated pipe or kinking a hose to make it reach.

Mr. Gasket 2670BK GM LS Swivel Water Neck Features:

• Fits 1997-2020 GM Gen III and Gen IV LS based engines. Will not fit 2013-up Gen V engines.
• Neck rotates 360 degrees at a 30 degree angle for maximum versatility in engine swaps.
• Die cast aluminum for strength, durability and corrosion resistance.
• Thick mounting flange prevents warping and provides a positive coolant seal.
• Satin black finish for a modern custom appearance.
• Stainless steel Allen head cap screws mount flush with the top of the flange.
• Uses commonly available 1-1/2 in. radiator hose, casting inside diameter 1-3/16 in.
• 1997-2003 and 2009 engines require a 2004-2008 style thermostat such as 6367 at 160 degrees or 6368 at 180 degrees.