Mercruiser Circulating Water Pump Bi-Directional 8503991 GM Small Block V6 V8 18-684M 835390-6 856364-5 3853850 385198

Mercruiser Circulating Water Pump Bi-Directional 8503991 GM Small Block V6 V8 18-684M 835390-6 856364-5 3853850 385198

New Sierra 18-3599-2 bidirectional circulating water pump for Crusader, MerCruiser, OMC, Pleasurecraft, and Volvo Penta marine gas V6 and V8 engines. Fits most GM/Chevrolet V6 (4.3L 262 cu-in) and small block V8 (5.0L 305 cu-in and 5.7L 350 cu-in) engines.

The Sierra 18-3599-2 replaces and supersedes Sierra part numbers 18-3599-1, 18-3599, and 18-3583. It fits both composite and steel timing covers. Replaces these OEM part number:

Brand    Part Number
Crusader    7142520, 20318
MerCruiser/Mercury    8503991, 17437, 60658, 850399, 811841
OMC    985429, 980477, 382218, 3853850
Pleasurecraft    RA057018
Volvo Penta    856364-5, 3853850, 835390-6, 3851982-3, 3853850