Osco Marine Manifolds
Since 1932
OSCO Motors Co. has been in the business of providing boaters with a high quality, reasonable cost alternative to original manufacturer's equipment.
All manifolds come with a 3 year warranty and DO NOT include gaskets. Order gaskets and bolts separately. We stock all OSCO manifolds and ship the same day.
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Save $20.00 when you order 2 manifolds

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1. 7114B2 Manifold. Fits 305 - 350 cu.in. GM small block V8 engines. Fits both sides of engine. Replaces Mercruiser #’s 87114 and 860246. Updated to replace all small block Mercruiser center riser manifolds to date. Use mounting kit 7214-MK.

2.7214-MK Mounting Kit, manifold. Fits 7234B and 7235B manifolds. Includes CV-GH gasket and mounting hardware.

3. CV-GH Gasket, manifold to cylinder head. Included in 7214-MK mounting kit. Replaces Mercruiser # 27-33395.

4. 4354 Riser, 4" exhaust outlet, 7º down angle. For late model inboard/outboard and inboards.
Replaces Mercruiser # 44354, 807914 and 807988. Use mounting kit 4354-MK.

5.4354-MK Mounting Kit, riser. Fits 4354 riser. Includes 8503-GR gasket and mounting hardware.

6. 8503A Riser, 3" exhaust outlet, 15º down angle. For early model inboard/outboards. Replaces
Mercruiser #’s 98503 and 98504. Use mounting kit 8503A-MK.

7. 8503A-MK Mounting Kit, riser. Fits 8503A riser. Includes 8503-GR gasket and mounting hardware.

8. 8503-GR Gasket, restrictor. Fits center riser Mercruiser. Common use is on all raw water cooled motors.Restricts flow, creating water back pressure to keep manifold and/or spacer full. Replaces Mercruiser # 27-41813.

9. 8503-GB Gasket, blocked. Fits center riser Mercruiser. For fresh water/closed cooling, gasket separates anti-freeze and raw water (no stainless plate required). Replaces Mercruiser # 27-41811.

10. 8503-GO Gasket, open. Fits center riser Mercruiser. Common use is at base of spacer block along with 8503-GR at riser. Allows spacer to fill with water. Replaces Mercruiser # 27-87105.

11. 3320 Spacer, 3" center riser. Fits 9745 manifold. Replaces Mercruiser # 93320. Sold each. Use mounting kit 3320-MK with 8503A riser or use 3320-MK-X with 4354 riser.

12 3320-MK Mounting Kit, spacer. Fits 3320 spacer with 8503A riser. Includes 8503-GO and 8503-GR gaskets and
mounting hardware to bolt 8503A riser and 3320 spacer to 9745 manifold.

13. 3320-MK-X Mounting Kit, spacer. Fits 3320 spacer with 4354 riser. Includes 8503-GO and 8503-GR gaskets and mounting hardware to bolt 4354 riser and 3320 spacer to 9745 manifold.

14. 3322 Spacer, 6" center riser. Fits 9745 manifold. Replaces Mercruiser # 93322. Sold each. Use mounting kit 3322-MK to mount spacer to manifold. Riser #’s 8503A or 4354 will require their own mounting kit.

15. 3322-MK Mounting Kit, spacer. Fits 3322 Spacer. Includes 8503-GO and 8503-GR gaskets and mounting hardware to bolt spacer to manifold. Riser #’s 8503A or 4354 will require their own mounting kit.

16.F68C9 Water Fitting, 90º elbow. 3/4" MPT x 1" hose barb. Replaces Mercruiser # 22-36305.

17. F68CS Water Fitting, straight. 3/4" MPT x 1" hose barb. Replaces Mercruiser # 22-45084.

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