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Mercruiser Thermostat Housings

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Engine / Model

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Ending S/N

Sierra Thermostat Housing

Mallory Thermostat Housing

185 (229 CID)6330183691965518-1994(9) 9-42502
185 (262 CID)A331455B52795418-1994(9) 9-42502
200 GM6218462B52598118-1994(9) 9-42502
200/5.0L GM(3)B525982UP18-1994(9) 9-42502
200/5.0L GM(4)B525982UP18-1994(9) 9-42502
205 (262 CID)A331455B52795418-1994(9) 9-42502
205/4.3L, 4.3LX (262 CID)(3)B527955D71436918-1994(9) 9-42502
228 GM4765100621846118-1993 -
228 GM6218462B52598118-1994(9) 9-42502
230 GM6218462B52598118-1994(9) 9-42502
230/5.0L-LX GM(3)B525982F60099918-1994(9) 9-42502
230/5.0L-LX GMB525982F60099918-1994(9) 9-42502
250 GM4768000490884918-1993 -
255 GM4175500476799918-1993 -
260 GM6218462B52598118-1994(9) 9-42502
260/5.7L GM(3)B525982F60099918-1994(9) 9-42502
350 MagB525982F60099918-1994(9) 9-42502
5.7 GM (SKI)A338553B51462618-1994(9) 9-42502
280 GM TRS4176250477019918-1993 -
300 MR/TRS GM6668677B43036718-1994(9) 9-42502
500(Gen V)F213293F61576618-1994(9) 9-42502

Engine / Model

Beginning S/N

Ending S/N

Sierra Thermostat Housing

Mallory Thermostat Housing

Notes:
(3) : Old Design
(4) : New Design
(9) : For stainless steel version use 18-1989
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Engine / Model

Blowout
Save 16%-48% Off.
Thermostat Housing Kit - 18-1910 - Sierra
Meltdown Sale Price: $93.59 (Out of stock)
Save: $39.79
(29% Off $133.38)
Part # 18-1910 ValueShip™ Eligible
Replaces OEM part #
  • MERCURY MARINE 861493A3
Fits: 3.0L GM 181 L/4 (1999-Up)
Thermostat Housing - 18-1977-1 - Sierra
Meltdown Sale Price: $35.99
Save: $34.04
(48% Off $70.03)
Part # 18-1977-1 ValueShip™ Eligible
SHIPS TOMORROW!* if ordered in 22 hrs 48 mins.
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Replaces OEM part #
  • MERCURY MARINE 47441A1
Fits: 225, GM 260, 228, 898/198, 185R, 898R, 228R, 2GR, 350 Mag
Thermostat Housing, Stainless Steel - 18-1989 - Sierra
Your Price: $183.98
Save: $82.72
(31% Off $266.70)
Part # 18-1989 ValueShip™ Eligible
SHIPS TOMORROW!* if ordered in 22 hrs 48 mins.
Hurry! Only 1 left in stock
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Replaces OEM part #
  • MERCURY MARINE 860256A4
  • MERCURY MARINE 861006A
  • MERCURY MARINE 87290A4
(Use 18-1989K Thermostat Service Kit for replacement parts)
Thermostat Service Kit - 18-1989K - Sierra
Meltdown Sale Price: $9.96
Save: $3.44
(25% Off $13.40)
Part # 18-1989K ValueShip™ Eligible
SHIPS TOMORROW!* if ordered in 22 hrs 48 mins.
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Service Kit for 18-1989 Thermostat Housing
Thermostat Housing - 18-1993 - Sierra
Meltdown Sale Price: $221.39
Save: $42.61
(16% Off $264.00)
Part # 18-1993 ValueShip™ Eligible
SHIPS TOMORROW!* if ordered in 22 hrs 48 mins.
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Replaces OEM part #
  • MERCURY MARINE 78984A1
Thermostat Housing - 18-1994 - Sierra
Meltdown Sale Price: $142.19
Save: $45.99
(24% Off $188.18)
Part # 18-1994 ValueShip™ Eligible
SHIPS TOMORROW!* if ordered in 22 hrs 48 mins.
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Replaces OEM part #
  • MERCURY MARINE 87290A4
For: Stainless Steel Version use 18-1989
Thermostat Housing - 18-3531 - Sierra
Meltdown Sale Price: $280.79
Save: $105.90
(27% Off $386.69)
Part # 18-3531 ValueShip™ Eligible
SHIPS TOMORROW!* if ordered in 22 hrs 48 mins.
Hurry! Only 1 left in stock
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Replaces OEM part #
  • MERCURY MARINE 861188A1
Fits: MCM/MIE GM V-6 & V-8 305, 350, 454 & 502 cid engines with closed cooling systems
Thermostat Housing & Cover - 18-3532 - Sierra
Your Price: $169.99
Save: $74.01
(30% Off $244.00)
Part # 18-3532 ValueShip™ Eligible
SHIPS TOMORROW!* if ordered in 22 hrs 48 mins.
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Replaces OEM part #
  • MERCURY MARINE 55331A5
Fits: MCM/MIE GM V6 & V8, 305, 350, 454, and 502cid, engines with closed cooling
Mallory Thermostat Housing 9-42502
Mallory Thermostat Housing 9-42502
Your Price: $160.99
Save: $27.19
(14% Off $188.18)
Part # 9-42502 ValueShip™ Eligible
SHIPS TOMORROW!* if ordered in 22 hrs 48 mins.
Hurry! Only 1 left in stock
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Replaces GLM #:N/A
Replaces Original Equipment Manufacturer(OEM):Mercruiser
Replaces Original Equipment Manufacturer # (OEM #):87290A4
Fits Application:MCM/MIE GM V6-V8 (305,350,454,502 & 504 cid) early design
Mallory Thermostat Housing 9-42501
Mallory Thermostat Housing 9-42501
Meltdown Sale Price: $217.35
Save: $150.00
(40% Off $367.35)
Part # 9-42501 ValueShip™ Eligible
SHIPS TOMORROW!* if ordered in 22 hrs 48 mins.
Hurry! Only 1 left in stock
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Replaces Original Equipment Manufacturer(OEM):Mercruiser
Replaces Original Equipment Manufacturer # (OEM #):861188A1
Fits Application:MCM/MIE GM V6-V8 (305,350,454,& 502) w/ closed cooling
Mallory Thermostat Housing 9-42505
Mallory Thermostat Housing 9-42505
Meltdown Sale Price: $121.66
Save: $81.98
(40% Off $203.64)
Part # 9-42505 ValueShip™ Eligible
SHIPS TOMORROW!* if ordered in 22 hrs 48 mins. Replaces Original Equipment Manufacturer(OEM):Mercruiser
Replaces Original Equipment Manufacturer # (OEM #):90736A18
Fits Application:MCM/MIE 185 (229 cid) 330, 340, 7.4L, 454 Mag, 370, 425 & 465
Mercury Marine 47442 A1 replacement parts
Mallory Thermostat Housing 9-42503
Meltdown Sale Price: $34.11
Save: $22.14
(39% Off $56.25)
Part # 9-42503 ValueShip™ Eligible
SHIPS TOMORROW!* if ordered in 22 hrs 48 mins.
Hurry! Only 1 left in stock
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Replaces Original Equipment Manufacturer(OEM):Mercruiser
Replaces Original Equipment Manufacturer # (OEM #):47442A1
Fits Application:MCM/MIE GM V6-V8 (454 & 502cid) & Hi Perf. 454/482 cid (Off-set Bolt pattern)
Thermostat Housing
Your Price: $324.40
Save: $93.10
(22% Off $417.50)
Part # 18-3530-1 ValueShip™ Eligible
SHIPS TOMORROW!* if ordered in 22 hrs 48 mins.
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  • Replaces: 860256A4
  • For: GM V6 and V8 (305 & 350 ci)
Chrysler Elbow - H2O
Your Price: $103.49 (Out of stock)
Save: $115.70
(52% Off $219.19)
Part # T-20913 ValueShip™ Eligible
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Replaces:
  • Chrysler #'s 2469639 and 2847405
Mercruiser Elbow - H2O
Your Price: $175.18
Save: $148.82
(45% Off $324.00)
Part # T-20978 ValueShip™ Eligible
SHIPS TOMORROW!* if ordered in 22 hrs 48 mins.
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Replaces:
  • Mercruiser #'s 76771 and 60427.
Sierra
Average Customer Review for Thermostat Housing Kit - 18-1910 - Sierra
Full StarFull StarEmpty StarEmpty StarEmpty Star Based On 1 Review | Write Review
Full StarFull StarEmpty StarEmpty StarEmpty StarMissing Pieces
by Karen from Palmetto, Florida on July 10, 2015
Thermostat and plastic sleeve for the thermostat were missing. Bolts that should be in the kit that mount the thermostat to the head were substituted for bolts that that don't fit anything on a Mercruiser 3.0...I know because I know every nut and bolt on this engine. They are so big they won't even fit through the holes of the thermostat housing, let alone anything else. Plus the bolts that were provided are cheap carbon steel. Ok for fresh water, completely useless for salt. Moral of the story: don't buy this stuff online unless it's genuine Mercruiser or Quicksilver. All of these boat part websites are selling the same junk. The sad thing is, I bought an exhaust elbow from iboats.com on this same order and it came with more parts than expected plus the bolts were stainless steel. Go figure.
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Average Customer Review for Mallory Thermostat Housing 9-42505
Full StarFull StarFull StarFull StarFull Star Based On 1 Review | Write Review
Full StarFull StarFull StarFull StarFull StarMercruiser Chevy big block 454 cid
by Thomas from Highlands, New Jersey on July 07, 2015
Fits and works as expected. Mallory t-stat housing several hundred dollars less than Mercruiser part. Fully painted inside which should protect it from rusting. I boat in sal er, but only have a couple hours of use on it.
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Q:
Will this fit my 2005 mercruiser 3.0 ?
A:
Yes, based on the information you have provided, this should work for your application.
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