GLM exhaust manifold applications

GLM Mercruiser manifolds, elbows – risers, bellows for
4.3, 5.0 and 5.7 liter up to 260 hp. Chevy small block engines

Updated April 30 2026

Mercruiser exhaust manifolds from 120 – 260 hp. with V6 and V8 models
Manifold and risers available for GM 4.3 liter 262, small block Chevy 5.0 liter 305 or 5.7 liter 350 engines
Mercruiser exhaust manifolds and conversion kits from 1 piece to 2 piece available for V6 models
For manufacturing information, please contact GLM Marine for exhaust manifolds
Exhaust manifolds with increased water cooling area over the Mercruiser OEM unit and come with a full 3 year manufacturer warranty
Exploded view Mercruiser drawings for help with parts

Click on manifords and risers to see exploded view of parts included

58231 Mercruiser parts 3" elbow / manifold set

$1095.99 US

$ 1,533.99 CDN

GLM Marine aluminum manifold

P/N 58231

Complete GLM Marine Mercruiser manifold and riser for GM V8 engines for Chevy exhaust manifolds with 3 inch riser.

GLM Marine Mercruiser small block exhaust manifolds included:

P/N 51230 Exhaust manifold (2 units) V8 Chevy cast iron assembly OEM number 860246 Q11
P/N 51110 Riser 3 inch x 2 OEM number 98504 A3 V8 Chevy

P/N 31100 Gasket OEM number 27 – 33395 x 2
P/N 30240 Gasket OEM number 27 – 863724 x 2
P/N 13991 90 degree hose fitting / 22 – 806926 x 2
P/N 13992 Drain plug OEM number 22 – 806608 A02 x 2
P/N 80140 O ring for plug / 25 – 45253 x 2
P/N 22391 Stud OEM number 16 – 49545 x 8
P/N 21248 Locknut / 11 – 46335 x 8

parts are compatible with:

305 V8 200, 1985 – 1987 (S/N 6899058 – 0B 774444)
228, 1983 – 1995 (S/N 6218462 – 0F 600999)
230, 1985 – 1987 (S/N 6899269 – 0B 773739)
230 MEI, 1981 – 1987 (S/N 5907058 – 0B 788151)

5.0L, 1988 – 1995 (S/N 0B 774445 – 0F 600999)
5.0L EFI Gen +, 1998 – 2001, (S/N 0L 012052 – Up)
5.0L LX, 1988 – 1995 (S/N 0B 773740 – 0F 600999)
898, 1983 – 1984 (S/N 6218462 – 6899057)
260, 1983 – 1987 (S/N 6218462 – 0B 773304)
260 MEI, 1981 – 1987 (S/N 5907058 – 0F 024999)
300, 1985 – 1986 (S/N 6668677 – 0B 430367)
320 EFI 1987 – 1989 (S/N 0A 543604 – 0C 622418)
350 MAG Alpha 1986 – 1987 (S/N 0A 635178 – 0K 999999)
350 MAG Alpha EFI 1996 – 1997 (S/N 0F 800300 – 0K 999999)
350 MAG Bravo MPI, 1995 – 1997 (S/N 0F 415189 – 0K 999999)
350 MAG EFI Ski, 1994 – 1997 (S/N 0F 215561 – 0K 999999)
350 MAG MPI Horizon 1998 – 2001 (S/N 0L 010019 – up)
350 Mag MPI MIE, 1998 – 2001 (S/N 0L 002008 up)
350 Mag MPI Ski, 1995 – 1996 (S/N 0F 350583 – 0F 79 9999)
350 Mag MPI Ski Gen +, 2001 – up (S/N 0M 300000 – up)

5.7L, 1988 – 2001 (S/N 6218462 – up)
5.7L EFI 1995 – 2001 (S/N 0F 225560 – up)
5.7L EFI MIE, 1997 (S/N 0K 40300 – 0K 999999)
5.7L MIE Gen +, 1998 – 2001 (S/N 0L 002003 – up)
5.7L Ski, 1985 – 2001 (S/N 0A 338533 up) 5.7L LX
350 / EFI / Bravo, 1996 – 1997 (S/N 0F 601000 – 0K 999999)
377 Scorpion MCM, 2001 – 2001 (S/N 0L 416146 up)
377 Scorpion Ski, 1997 – 1998 (S/N 0K 000656 – up)
MX 6.2L MPI 377 / Horizon, 2000 – 2001 (S/N 0L 68003 – up)

58232 GLM Marine Mercruiser years 1983 to 2001 exhaust manifolds
4" kit

$1061.99 US

$ 1,486.99 CDN

P/N 58232

Mercruiser manifold and riser for GM V8 engine parts for small block Chevy exhaust manifolds with 4 inch riser.

small block exhaust manifolds included:

P/N 51230 Exhaust manifold (2 units) V8 small block chevy cast iron assembly OEM number 860246 Q11

P/N 51140 Riser 4 inch x 2 OEM number 807988 A2 V8 small block Chevy
P/N 31100 Gasket OEM number 27 – 33395 x 2
P/N 30240 Gasket OEM number 27 – 863724 x 2
P/N 13991 90 degree hose fitting / 22 – 806926 x 2
P/N 13992 Drain plug OEM number 22 – 806608 A02 x 2
P/N 80140 O-ring for plug / 25 – 45253 x 2
P/N 22391 Stud OEM number 16 – 49545 x 8
P/N 21248 Locknut / 11 – 46335 x 8

engine parts compatible with:
Same as the above manifold and riser set

Mercruiser 5.0 and 5.7 liter manifolds for V8 engine
GM 305 / 350 / 377 cubic inch. Years 1983 and up
*For 1977 – 1982 end rise exhaust manifold log style, see below section

58990 Mercruiser conversion kit V8 4 inch manifolds and risers

$1836.99 US

$ 2570.99 CDN

P/N 58990

Mercruiser exhaust manifold conversion kit. Convert the older style ‘log style’ end rise assembly to the center rise assembly.

Manifold and riser set are all the engine parts listed for P/N 58232 (shown above), plus parts shown below.

GLM Marine Mercruiser exhaust manifold and riser set includes the following engine parts:

P/N 51230 Cast iron exhaust manifolds Mercruiser OEM number 860246 Q11x 2 units
P/N 13222 Thermostat housing kit
P/N 13030 Thermostat / 807052 T1
P/N 47180 Water hose
P/N 89120 Upper bellow / 32 – 44348 T x 4
P/N 01100 Hose clamp / 54 – 815504372 x 16
P/N 50770 Tube x 2
P/N 01057 Small hose clamp x 8
P/N 50011 Solenoid bracket
P/N 22303 Screw x 2
P/N 50012 Fuel filter bracket
P/N 21026 Spacer
P/N 22371 Screw / 331999
P/N 74009 Alternator bracket / 93175T
P/N 21695 Spacer for alt. bracket / 23 – 33186
P/N 22355 screw OEM number 10 – 12244 x 3
P/N 13992 Drain plug / 22 – 806608 A02 x2

51230 V8 350 GM exhaust manifold kit OEM 860246 A10

$379.99 US

$ 531.99 CDN

P/N 51230

Mercruiser V8 exhaust manifold with gasket OEM number 860246 A10.
GLM Marine Mercruiser engine parts used on either port and starboard sides.
Exhaust manifolds for V8 small block chevy
Cast iron assembly OEM number 860246 Q11

51140 Exhaust elbow 4 inch 7 degree OEM 807988 A2

$336.99 US

$470.99 CDN

P/N 51140

GLM Marine Mercruiser exhaust riser

4″ hose fitting at 7 degrees
Used on both port and starboard side.
Mercruiser OEM number 99746 A17.

51230 - 51110 Exhaust manifold kit 1985 to 1987

$727.99 US

$1019.99 CDN

P/N 51230 – 51110

Mercruiser exhaust manifolds for 3 inch hose.

Mercruiser exhaust manifold and riser set includes the following engine parts:

P/N 51230 Exhaust Manifolds
P/N 51110 riser
P/N 13990 Hose fitting with drain plug and o -ring
P/N 30240 Gasket OEM number 27- 863724
P/N 31100 Gasket OEM number 27 – 333951 and 5504372
P/N 21891 Plug 3/4 inch -14 (Steel)
OEM number 22 – 41622

58660 Mercruiser exhaust manifold elbow set without spacer

P/N 58660 Dry joint exhaust manifold alternative – complete kit (for one side only). Replaces the 2003 and up Mercury dry joint system.

Mercruiser parts included:

P/N 51148 Dry joint elbow
P/N 51230 manifold assembly / 860246 A10
P/N 30240 gasket OEM number 27 – 863724
P/N 31100 gasket OEM number 27 – 333951 and 5504372
P/N 22398 Screw with hex flange / 10 – 865982 057 x 4
P/N 21493 Lockwasher / 13 – 35048
P/N 13990 Hose fitting with drain plug and o -ring / 22 – 806926 A1

Sierra 5.0 and 5.7 liter GM V8 for years 1977 to 1982 with end riser (log style)

18-1950-1 Sierra manifold port side 18-1950-1 Port manifold

18-1951-1

Starboard exhaust manifold

P/N 18 – 1950 – 1 Sierra

or 18 – 1951 – 1 Sierra

replaces OEM numbers 77235 A2, 77235 A8, GLM 51237, 77234 A2. GM small block, 5.0L, 5.7L 305 / 350 V8 models with end rise ‘log style’ port or starboard.

Included

Sierra 18 – 2949 Gasket
Sierra 18 – 8548 Mounting Kit

Sierra Marine engine parts compatible with:
5.0L 198 MIE 305, 8 4 1977 (S/N 4776402 – 4931009)
5.0L 228, 305, 1977 – 1982 (S/N 4888930 – 6218461)
5.0L 228 TR 305, 1977 – 1978 (S/N 4888930 – 5170008)
5.0L 228 MIE 305, 1977 – 1980 (S/N 4888930 – 5907057)
5.0L 898 305, 1977 – 1982 (S/N 4762210 – 6218461)
5.7L 250 350, 1977 (S/N 4768000 – 4908849)
5.7L 255 GM 350, 1976 (S/N 4499061 – 4767999)
5.7L 255 MIE GM 350, 1976 – 1980 (S/N 4499061 – 5907057)
5.7L 260 350, 1978 – 1982 (S/N 4908850 – 6218461)
5.7L 280 TRS 350, 1975 – 1976 (S/N 4176250 – 4770199)

Inline 4 cylinder, 3.0L , GM 181 (1990 and up) manifolds and risers

3 liter 4 cylinder inline 860235A03

$714.99 US

$999.99 CDN

P/N 51214

Exhaust manifold replaces 860235 A03. Inline 4 cylinder 181

(1990 and up, serial numbers 0C 856559 – up). New design with moulded end caps.

Parts included:

P/N 51214 Manifold casting
P/N 33580 Exhaust gasket / 27 – 815528
P/N 32180 carburetor base gasket, 27 – 807982
P/N 13980 Straight fitting / 22 – 862557
P/N 31430 Thermostat gasket / 24 – 47590 – 1
P/N 13991 90 degree hose fitting / 22 – 862210 A01
P/N 22475 Stud x 4 /6 – 806300
P/N 22280 Cap / 764799
P/N 21248 Nuts x 4 / 11 – 46335

4 cylinder engine parts for 140 GM exhaust manifolds years 1968 to 1982 End rise style

51212 Inline exhaust manifold 4 cylinder years 1968-1982

$714.99 US

$999.99 CDN

P/N 51212

Exhaust manifold replaces 96705A1. 140, 4 cylinder 181 (1968 – 1982) end rise exhaust manifold.

GLM Marine parts included:

P/N 51213 casting
P/N 31570 gasket / 27 – 53354
P/N 30920 gasket, end cap / 27 – 807218
P/N 31520 riser gasket / 27 – 99777 – 2
P/N 31660 Carburetor base gasket / 27 – 64692
P/N 51030 End cap gasket / 73813 A1
P/N 22443 End cap screw / 10 – 25299
P/N 51010 end cap OEM number 60252 A2
P/N 21756 End cap screw / 10 – 37562
P/N 22482 Stud – carburetor / 16 – 70236
P/N 13980 Straight fitting / 22 – 862557
P/N 21887 Plug / 22 – 36382
P/N 21248 Nut / 11 – 49838

4.3L V6, GM 229/262 (1983 – up) Manifolds and risers

58222 Mercruiser manifold years 1986 to 2001

$1072.99 US - w/ 4 inch riser

$1500.99 CDN - w/ 4 inch riser

P/N 58221 / 58222 Complete GLM Marine Mercruiser GM V6 / 4.3 Liter manifold set with 4 inch inch exhaust riser.

*If you require the 3 inch riser, please call for availability

Mercruiser exhaust manifold and riser set includes the following engine parts:

P/N 51220 Exhaust manifold assembly / 99746 A17 x 2
P/N 51110 / 98504 A3 or 51140 / 807988 A2 Elbow (3 inch or 4 inch) x 2
P/N 32170 Mounting gasket OEM number 99757 x 2
P/N 30240 gasket / 27 – 863724 x 2
P/N 13991 90 degree hose fitting / 22 – 806926 x 2
P/N 13992 drain plug OEM number 22 – 806608 A02 x 2
P/N 80140 O-ring for plug / 25 – 45253 x 2
P/N 22391 stud OEM number 16 – 49545 x 8
P/N 21248 Flange nut / 11 – 46335 x 8

Compatible with

185 (4 bbl.) 229, 1983 – 1984 (S/N 6330183 – 6919655)
175 – 262, 1987 (S/N 0B 527955 – 0B 773242)
185 (2 bbl.) 262, 1985 – 1986 (S/N 0A 331455 – 0B 527954)
205 – 262, 1985 – 1987 (S/N 0A 331455 – 0B 775129)
4.3L 262, 1988 – 1996 (S/N 0B 773243 – 0F 802999)
4.3L / LH (Gen + and EFI) 262, 1998 – 2001 (S/N 0L 010044 – up)
4.3L MPI 262, 2001 (S/N 0M 300000 – up)
4.3L LX (4 bbl.) 262, 1996 – 1998 (S/N 0B 775130 – 0F 802999)
4.3L (Gen +, 2 bbl.), 1996 – 2001 (S/N 0F 803800 – 0K 999999)
4.3LXH (Gen +) 262, 1996 – 1997 (S/N 0F 803814 – 0K 999999)

$ 1,298.89 CDN with 4 inch riser

58650 V6 manifold and exhaust elbow with gaskets and bolts

P/N 58650

GLM dry joint replacement conversion to wet joint for V6 Mercruiser 2003 and up.

$659 US or

$929 cdn.

Assembly replaces one side (port or starboard) of existing Mercury dry joint assembly. This new type will change your external water ports to internal ports or (wet joint type).

Included

P/N 51148 Dry joint exhaust riser
P/N 51220 / 99746 A17 Exhaust manifold
P/N 30240 Exhaust gasket / 27 – 863724
P/N 32170 Mounting gasket OEM number 99757
P/N 13990 Hose fitting with drain plug kit / 22 – 806926 A1
P/N 22398 Mounting screw / 10 – 865982 057
P/N 21493 Lockwasher / 13 – 35048

51220 GM V6

$397.99 US

$556.99 CDN

P/N 51220

V6 exhaust manifold casting with installation exhaust gasket. Replaces Mercury 99746 A17
GLM Marine parts are compatible with starboard or port side.
Includes P/N 30270 gasket and P/N 32170 gasket

51110 exhaust Riser 15 degree 260

$348.99 US

$488.99 CDN

P/N 51110 Exhaust elbow

3 inch hose fitting length
15 degree.

51220 - 51110 Alpha LX EFI MAG

$745.99 US

$1044.99 CDN

P/N 51220 – 51110

Port or starboard side exhaust manifold kit, for 3 inch hose.

Included

P/N 51220 exhaust manifold
P/N 13990 Hose fitting with drain plug and o -ring
P/N 30240 Gasket OEM number 27- 863724
P/N 32170
P/N 22391
P/N 51110 exhaust riser

51220-51140

$745.99 US

$1044.99 CDN

P/N 51220 – 51140

Port or starboard side manifold kit, for 4 inch hose.

Mercruiser exhaust manifold and risers parts included:

P/N 51220 Exhaust manifold
P/N 13990 Hose fitting with drain plug and o -ring
P/N 30240 Gasket OEM number 27 – 863724
P/N 32170 Mounting gasket OEM number 99757
P/N 22391
P/N 21892
P/N 22379
P/N 51140 Exhaust manifold and riser
P/N 22381 x 4

51230-51140

$715.99 US

$999.99 CDN

P/N 51230 – 51140

Port or starboard side manifold kit, for 4 inch hose.

Mercruiser exhaust manifold and risers parts included:

P/N 51230 Exhaust manifold
P/N 13990 Hose fitting with drain plug and o -ring
P/N 30240 Gasket OEM number 27 – 863724
P/N 32170 Mounting gasket OEM number 99757
P/N 22391
P/N 21892
P/N 22379
P/N 51140 Exhaust manifold and riser
P/N 22381 x 4

89130 Lower bellow

$32 US

$ 45.89 CDN

P/N 89130

Mercruiser bellow
lower 4″
fits P/N 51140 or 51145
OEM number 32 – 14358T
Use with 4 inch manifolds and risers

89120 Upper bellow

$34 US

$ 48.89 CDN

P/N 89120 Exhaust bellow

upper 4″
fits P/N 51140 or 51145
OEM number 32 – 4434 8T
Use with 4 inch manifolds and risers

89120 - 89130 Water hose

P/N 89120 – 89130

Upper and lower bellow kit.

Note 1 required for port
Note 1 for starboard.

89070 Upper bellow OEM 70981A3

$32 US

$ 46.89 CDN

P/N 89070

Upper 3″ bellow.
Used with P/N 51110 (98504 A3).
Lower end of hose measures 4 inches.

50300 exhaust riser spacer

$143.99 US

$200.99 CDN

P/N 50300

3″ spacer

Used to raise height for hose fitting. 6 inch also available.
Can be used on both port or starboard side of GM V8 or V6 models.
OEM number 93320 A14.

Why you need to replace the manifolds and risers before they fail

When the motor overheats, this can be caused by any number of problems but they are almost always caused by an issue with the cooling system, either in the motor’s system or the outdrive system. Sometimes, a simple failed impeller in the outdrive can be the culprit which is an easy fix; but many times it is a leaking exhaust manifold which can be the cause of lack of water circulation leading to motor over heating.

An overheating engine that is not shut down in time can lead to anything from a damaged head gasket to warped cylinder heads. Another major motor issue that can arise when there is a leak is that the water can mix into the exhaust gas internal area, and end up in the engine leading to the pistons locking up which ultimately can lead to complete engine failure.

Unfortunately, there is no easy way to prematurely detect when a manifold leak may occur as there are no warning signs or symptoms. When a manifold leak happens, it happens right away.
Extending the life of your Mercruiser cooling system – winterizing or flushing out salt water

In any region where winter causes temperatures to dip below the freezing mark

Properly winterizing the boat is essential. Part of winterizing means flushing out all of the water in the manifold and cooling system and risers. If water is left to sit in it during the winter, the water can easily freeze and expand causing the cast iron assembly to form cracks that aren’t visible, leading to a leak – which can cause major issues with overheating.

In regions where the boat is being used in salt water, such as Florida, it is important to regularly flush out the salt water in the cooling system with fresh water from a hose. This will extend the life of your exhaust manifold assemblies as salt water sitting inside the system can lead to premature corrosion leading to manifold leaks.

Standard Mercruiser OEM manufactured castings

Can have uneven internal wall thickness due to their manifold casting processes. GLM Marine uses a ‘lost foam casting ’ process, allows for more accurate manifold casting of the wall between the water jacket and exhaust gas area. This prevents thin spots in the wall which lead to pre-mature failure.

The GLM brand is also designed with a larger water cooling area, up to 40% more compared to original OEM models.

This can help reduce the overall temperature, leading to longer gasket life. The internal area has also been designed to prevent back pressure or excessive turbulence. Need help contact us