For Indmar V8 “small block” engine cooling systems.

also crosses with:
Sierra: 18-3599-2
API Marine: WP1500
Barr: MC-2-17437
Crusader: 20318
GLM: 15201
Indmar: S551045
Mallory: 9-42606
MES: WP453ML
Pleasurecraft: RA057018