Sierra / Mallory

Additional Details:

• Fits: MCM 120 (1993 & newer), 140/3.0L, 470, 165 in-line 6 cyl., GM V-8 small block (1982 & older)
• Fits: Ford V-8 engines

Interchanges/Replaces

Barr

• MC472799777

GLM

• 31520

Mallory

• 9-61407

Mercruiser Stern Drive

• 27-52076
• 27-99777
• 27-997771
• 27-997772
• 27-99777B2

Osco

• 52076

Additional Details:

• For: Closed cooling
• Fits: GM V-6 & V-8 with center rise outlet exhaust manifold

Use With:

• 18-1970-2: Riser Elbow
• 18-1976-2: Manifold Elbow
• 18-1908: Manifold Riser Spacer
• 18-1974-1: Elbow
• 18-1952-1: Manifold
• 18-1953-2: Manifold
• 18-1957-2: Manifold

Interchanges/Replaces

Barr

• MC 20 87918

GLM

• 30220

Mercruiser Stern Drive

• 27-41811
• 27-860231
• 27-863725
• 27-8637251

Osco

• 8503-GB

Interchanges/Replaces

OMC Stern Drive

• 910113

Exhaust Elbow Gasket
Replaces: Mercruiser 27-97542
For: 3.7L w/cast iron manifolds 1983-89
Our outdrive mounting gaskets are more tear resistant than the OEM and other aftermarket competitors and feature our exclusive “anti-stick” coating for easy removal the next time they need replaced.

Exhaust Elbow Gasket
Replaces: Mercury Marine 27-18272
For: 3.7L w/aluminum manifolds 1985-89
Our outdrive mounting gaskets are more tear resistant than the OEM and other aftermarket competitors and feature our exclusive “anti-stick” coating for easy removal the next time they need replaced.

Key Features:

• Barr, Indmar & Marine Power Ford Small Block V8 302-351 cu. in.
• GM Big Block V8 454 cu. in.
• GM Small Block V8 305-350 cu. in.

Additional Details:

• Description: Blocked

Use With:

• 18-1907: Riser
• 18-1939: Riser
• 18-1999: Manifold Elbow
• 18-2854-1: Exhaust Elbow Gasket

Interchanges/Replaces

Mallory

• 9-40173
• 9-40770

Osco

• 992-MK-FW
• CRR-MK-FW

List of Containing Parts

Sierra Item #	OE/Competitor #	Quantity	Description	Image	Comments
18-0476-1	Barr 01-0105 GLM 36820 Mallory 9-65500 Osco 992-G-FW	1	Riser Block Off Gasket		N/A
18-4258	Crusader 113186 GLM 21892 Mallory 9-41205 Mercruiser Stern Drive 22-33198 22-33198A1 22-41622 22-46754 Osco 1016012	1	Pipe Plug		N/A

Key Features:

• Crusader GM Small Block V8 305, 350
• Crusader GM Big Block V8 454

Use With:

• 18-1916: Riser

Interchanges/Replaces

Mallory

• 9-40476

Osco

• 7169-MK

List of Containing Parts

Sierra Item #	OE/Competitor #	Quantity	Description	Image	Comments
18-0305-1	Barr CR 47 C 96108 Crusader 96108 Mallory 9-65400 Osco 6108	1	Exhaust Elbow Gasket		N/A

Additional Details:

• For: Crusader GM Small Block V8 305, 350
• For: Crusader GM Big Block V8 454

Use With:

• 18-1927: Riser

Interchanges/Replaces

Mallory

• 9-40477

Osco

• 7772-MK

List of Containing Parts

Sierra Item #	OE/Competitor #	Quantity	Description	Image	Comments
18-0305-1	Barr CR 47 C 96108 Crusader 96108 Mallory 9-65400 Osco 6108	1	Exhaust Elbow Gasket		N/A

Additional Details:

• For: Mercruiser GM V-6 229 & 262 cu. in. (models 185 & 205)
• For: GM Small Block V-8 305-350 cu. in. (models 200, 228, 230, 260 & 898)
• For: GM Big Block V-8 454 cu. in. (models 330, 340 & 7.4L)

Use With:

• 18-1976-2: Manifold Elbow

Interchanges/Replaces

Mallory

• 9-40578

Osco

• 4354-MK

List of Containing Parts

Sierra Item #	OE/Competitor #	Quantity	Description	Image	Comments
18-0897	Barr MC 20 99208 MC47-27-41813 GLM 30240 Mallory 9-61413 Mercruiser Stern Drive 27-41813 27-860233 27-863724 Osco 8503-GR	1	Exhaust Elbow Gasket		N/A

Additional Details:

• Caution: Not for fresh water/closed cooling systems
• For: Mercruiser Ford Small Block V-8 302-351 cu. in. (models 215, 225, 233, 255 & 888)
• For: GM Small Block V-8 305-351 cu. in. (models 198, 228 & 898)

Use With:

• 18-1971: Elbow
• 18-1978: Elbow

Interchanges/Replaces

Mallory

• 9-40579

Osco

• 6371-MK-SP

List of Containing Parts

Sierra Item #	OE/Competitor #	Quantity	Description	Image	Comments
18-4008	Barr MC-20-60207 GLM 50006 Mallory 9-40540 Mercruiser Stern Drive 60207 Osco 60207	1	Block Off Plate		N/A
18-2833	Barr MC472799777 GLM 31520 Mallory 9-61407 Mercruiser Stern Drive 27-52076 27-99777 27-997771 27-997772 27-99777B2 Osco 52076	1	Exhaust Elbow Gasket		N/A
NSS	Mercruiser Stern Drive 11-49838	4	Nut	No Image	N/A
NSS	Mercruiser Stern Drive 13-35048	4	Lockwasher	No Image	N/A
NSS	Mercruiser Stern Drive 16-49545	4	Stud	No Image	N/A

Additional Details:

• For: Mercruiser GM V-6 229 & 262 cu. in. (models 185 & 205)
• For: GM Small Block V-8 305-350 cu. in. (models 200, 228, 230, 260 & 898)
• For: GM Big Block V-8 454 cu. in. (models 330, 340 & 7.4L)

Use With:

• 18-1974-1: Elbow
• 18-1970-2: Riser Elbow

Interchanges/Replaces

GLM

• 53300

Mallory

• 9-40580

Osco

• 8503A-MK

List of Containing Parts

Sierra Item #	OE/Competitor #	Quantity	Description	Image	Comments
18-0897	Barr MC 20 99208 MC47-27-41813 GLM 30240 Mallory 9-61413 Mercruiser Stern Drive 27-41813 27-860233 27-863724 Osco 8503-GR	1	Exhaust Elbow Gasket		N/A
NSS	Mercruiser Stern Drive 11-49838	4	Nut	No Image	N/A
NSS	Mercruiser Stern Drive 13-35048	4	Lockwasher	No Image	N/A
NSS	Mercruiser Stern Drive 16-49545	4	Stud	No Image	N/A

Additional Details:

• For: Mercruiser 4 cyl. 224 cu. in. 3.7L (models 165, 170, 180 & 190)

Use With:

• 18-1937: Elbow

Interchanges/Replaces

Mallory

• 9-40581

Osco

• 8561-MK

List of Containing Parts

Sierra Item #	OE/Competitor #	Quantity	Description	Image	Comments
18-0881-1	GLM 32470 Mallory 9-61412 Mercruiser Stern Drive 27-18272 27-97863 Osco 8561-G	1	Exhaust Elbow Gasket		N/A
NSS	Mercruiser Stern Drive 10-52143	4	Screw	No Image	N/A

Additional Details:

• For: 229 & 262 ci V-6, 305 & 350 SB V-8, 454 Big Block V-8

Use With:

• 18-1906: Manifold Spacer
• 18-1908: Manifold Riser Spacer
• 18-1908K: Manifold Riser Spacer Kit
• 18-1951-1: Manifold
• 18-1952-1: Manifold
• 18-1953-2: Manifold
• 18-1971: Elbow
• 18-1978: Elbow
• 18-2849-1: Exhaust Elbow Gasket
• 18-1970-2: Riser Elbow
• 18-1957-2: Manifold

Interchanges/Replaces

GLM

• 53330

Mallory

• 9-40582

Osco

• 3320-MK
• 6371-MK-SP

List of Containing Parts

Sierra Item #	OE/Competitor #	Quantity	Description	Image	Comments
18-0897	Barr MC 20 99208 MC47-27-41813 GLM 30240 Mallory 9-61413 Mercruiser Stern Drive 27-41813 27-860233 27-863724 Osco 8503-GR	1	Exhaust Elbow Gasket		N/A
18-2849-1	Barr MC 47 27 87105 GLM 32080 Mallory 9-61414 Mercruiser Stern Drive 27-818832 27-860232 27-863726 27-87105 27-871051 Osco 8503-GO	1	Exhaust Elbow Gasket		N/A

Additional Details:

• For: 229 & 262 ci V-6, 305 & 350 SB V-8, 454 Big Block V-8

Use With:

• 18-1908: Manifold Riser Spacer
• 18-1908K: Manifold Riser Spacer Kit
• 18-1952-1: Manifold
• 18-1953-2: Manifold
• 18-1957-2: Manifold
• 18-1976-2: Manifold Elbow

Interchanges/Replaces

GLM

• 53430

Mallory

• 9-40583

Osco

• 3320-MK-X

List of Containing Parts

Sierra Item #	OE/Competitor #	Quantity	Description	Image	Comments
18-0897	Barr MC 20 99208 MC47-27-41813 GLM 30240 Mallory 9-61413 Mercruiser Stern Drive 27-41813 27-860233 27-863724 Osco 8503-GR	1	Exhaust Elbow Gasket		N/A
18-2849-1	Barr MC 47 27 87105 GLM 32080 Mallory 9-61414 Mercruiser Stern Drive 27-818832 27-860232 27-863726 27-87105 27-871051 Osco 8503-GO	1	Exhaust Elbow Gasket		N/A

Key Features:

• OMC GM Small Block V8 305-350 cu. in. (1979-1989) & mult application for Ford & GM risers

Use With:

• 18-1921: Manifold Elbow

Interchanges/Replaces

Mallory

• 9-40670

Osco

• 9863-MK

List of Containing Parts

Sierra Item #	OE/Competitor #	Quantity	Description	Image	Comments
18-0943-2	Barr OMC 47 909786 GLM 33810 Mallory 9-61452 OMC Inboard 909786 OMC Stern Drive 351325 3850496 909786 913783 Osco 9863-G Volvo Penta 3850496 3863191	1	Exhaust Elbow Gasket		N/A

Additional Details:

• For: Pleasurecraft Ford Small Block V8 302 and 351 cu.in.

Use With:

• 18-1899: Riser

Interchanges/Replaces

Mallory

• 9-40871

Osco

• 29001-MK

List of Containing Parts

Sierra Item #	OE/Competitor #	Quantity	Description	Image	Comments
18-0677-1	GLM 33500 Mallory 9-65700 Osco M0002 Pleasurecraft RM0002	1	Elbow Gasket		N/A

Key Features:

• OMC/Volvo GM Small Block V8 305-350 cu.in.

Use With:

• 18-1909-1: Riser

Interchanges/Replaces

Barr

• CM 20 6674J P

Mallory

• 9-40672

Osco

• 50456-MK

List of Containing Parts

Sierra Item #	OE/Competitor #	Quantity	Description	Image	Comments
18-0943-2	Barr OMC 47 909786 GLM 33810 Mallory 9-61452 OMC Inboard 909786 OMC Stern Drive 351325 3850496 909786 913783 Osco 9863-G Volvo Penta 3850496 3863191	1	Exhaust Elbow Gasket		N/A
NSS	Mercruiser Stern Drive 13-35048	4	Washer (3/8)	No Image	N/A

Key Features:

• Volvo GM Small Block V8 305-350 cu.in.

Additional Details:

• Models: AQ & BB200, 205, 211, 231, 225, 260, 271, 290, 311, 500, 501, 570, 571 & 572

Use With:

• 18-1935-1: Riser

Interchanges/Replaces

Mallory

• 9-40972

Osco

• 56879-MK

List of Containing Parts

Sierra Item #	OE/Competitor #	Quantity	Description	Image	Comments
NSS	Volvo Penta 959796	2	Bolt, Zinc 5/16-18 x 5 1/2 Grade	No Image	N/A
18-4236	GLM 21725 Volvo Penta 941907	4	Washer
18-2971-1	Barr VO47-835908 GLM 35080 Mallory 9-65800 Osco 35908 Volvo Penta 835908 856039 857618	1	Exhaust Manifold Gasket		N/A

Use With:

• 18-1971: Elbow
• 18-1978: Elbow

Interchanges/Replaces

Barr

• MC20-60426P

GLM

• 53100

Mallory

• 9-40170
• 9-40586

Osco

• 6371-MK

List of Containing Parts

Sierra Item #	OE/Competitor #	Quantity	Description	Image	Comments
18-2833	Barr MC472799777 GLM 31520 Mallory 9-61407 Mercruiser Stern Drive 27-52076 27-99777 27-997771 27-997772 27-99777B2 Osco 52076	1	Exhaust Elbow Gasket		N/A
NSS	Mercruiser Stern Drive 11-49838	4	Nut	No Image	N/A
NSS	Mercruiser Stern Drive 13-35048	4	Lockwasher	No Image	N/A
NSS	Mercruiser Stern Drive 16-49545	4	Stud	No Image	N/A

Additional Details:

• Description: Open

Use With:

• 18-1907: Riser
• 18-1939: Riser
• 18-1999: Manifold Elbow
• 18-1971: Elbow

Interchanges/Replaces

Barr

• 20-0082-P

Mallory

• 9-40171

Osco

• 992-MK

List of Containing Parts

Sierra Item #	OE/Competitor #	Quantity	Description	Image	Comments
18-2854-1	Barr 01-0107 GLM 36830 Mallory 9-65501 Osco 992-G	1	Exhaust Elbow Gasket		N/A
18-4258	Crusader 113186 GLM 21892 Mallory 9-41205 Mercruiser Stern Drive 22-33198 22-33198A1 22-41622 22-46754 Osco 1016012	1	Pipe Plug		N/A