Mercruiser V6 & V8 Chevy GM 4" Engine Exhaust Riser Elbow 807988A2 807988Q03 18-1976-1 (GL51140)

GLM Manifolds are Superior in the Aftermarket Marine Parts Industry.

Designed to Increase Performance, Reduce Back Pressure
and Add More Horsepower to Your Engine!


 GLM Replacement 4" Exhaust Riser / Elbow Kit For MerCrusier Mercruiser V6 and V8 Small/Big Block Including Gasket & Mounting Bolts Fits MerCruiser GM V-6 & V-8 engines with center rise outlet exhaust manifold (2002 & older) 4 inch (102 mm) O.D.7 degree down angle Great for salt or Fresh water boats! GLM Part Number: 51140 In GLM's Mercruiser replacement 4 inch riser, there are two additional water jackets, allowing a higher volume of water to flow through the riser, keeping the engine cooler. The risers are powdercoated black for maximum corrosion protection Comparable Part Numbers: Mercruiser: 807988A2 , 807988q03 Sierra: 18-1976-1 Osco: 4354 Barr Marine: MC-20-44354 Kit Contains: 1) Exhaust Riser/Elbow 1) Plug 21892 1) Plug 22379 4) Screws 4) Lockwashers