Riser Mounting Kit, Mercruiser 4" (4354 Style )

Riser Mounting Kit For A Mercruiser V-6 or V-8 With 4 Inch Center Risers. Mercruiser Started Using 4 Inch Center Risers during 1986, Which Was A Transition Year to go From 3 Inch To 4 Inch. After 1986, they Are All 4 Inch. This Fits Center Riser Manifolds That Use an Osco Riser 4354, Or A GLM Riser 51140.