This Improved Racing PLM-M28 coolant plug seals the M28 x 1.25 mm block coolant port on GM Gen III, Gen IV and Gen V small block engines. It is machined from steel with a clear zinc plating and uses a bonded rubber sealing washer, replacing GM 11611351 and 12561663.

Improved Racing PLM-M28 Coolant Port Plug Features:

• Fits GM Gen III, Gen IV and Gen V LS and LT small block engines
• M28 x 1.25 mm thread
• Machined from steel with clear zinc plating
• Bonded sealing washer of zinc-plated steel and nitrile rubber with a self-centering feature
• Replaces GM part numbers 11611351 and 12561663