Engine Model	Serial Range	Thermostat	Gaskets	Housing	Thermostat Kit
60	1887079 - 2049044	18-3551
80	2049045 - 2851423	18-3551
90	2851424 - 3226957	18-3557	18-2831
110	1537370 - 2044033	18-3551
120(6)	1666601 - 3377340	18-3551
120(7)	1725593 - 2324346	18-3551
150	1666495 - 2048046	18-3551
160(6)	2048022 - 2770031	18-3551
160(7)	2048022 - 2233574	18-3557
160(7)	2326069 - 2770031	18-3557	18-2831
165	2770032 - 5813433	18-3550	18-2831		18-3650
190	1564539 - 1730903	18-3551
200	2453769 - 2712072	18-3557	18-2831
120(7)	2324347 - UP	18-3550	18-2831		18-3650
140 (4 CYL)	2508261 - UP	18-3550	18-2831		18-3650 (13)
140 (6 CYL)	1538930 - 1725960	18-3551
165	6916779 - UP	18-3555	18-2555		18-3667
170 (4 CYL)	6916779 - UP	18-3555	18-2555		18-3667
175(9)	B527955 - UP	18-3551	18-2552 (2)		18-3668
175 (8)	B527955 - UP	18-3551	18-2553 (1)		18-3668
175(9)	F001220 - UP	18-3649 (12)	18-2552 (2)		18-3648
180	6916779 - UP	18-3555	18-2555		18-3667
185 (229 CID)	6330183 - 6919655	18-3551	18-2553 (1)	18-1994 (14)	18-3668
185 (262 CID)	A331455 - B527954	18-3551	18-2553 (1)	18-1994 (14)	18-3668
190 (4 CYL)	6916779 - UP	18-3555	18-2555		18-3667
198 GM	4762210 - 6218461	18-3551	18-2844		18-3651
198 GM MCM	4762210 - 6218461	18-3649	18-2844 (4)		18-3646
198 GM MIE	4762210 - 6218461	18-3649	18-2844 (4)		18-3646
200 GM	6218462 - B525981	18-3551	18-2553 (1)	18-1994 (14)	18-3668
200	B525982 - F600999	18-3649	18-2917		18-3647
200(8)	B525982 - UP	18-3551	18-2553 (1)	18-1994 (14)	18-3668
200(9)	B525982 - UP	18-3649 (12)	18-2552 (2)	18-1994 (14)	18-3648
205 (262 CID)	A331455 - B527954	18-3551	18-2553 (1)	18-1994 (14)	18-3668
205(8)	B527955 - D714369	18-3551	18-2553 (1)	18-1994 (14)	18-3668
205(9)	B527955 - D714369	18-3551	18-2552 (2)		18-3668
205(9)	F001220 - UP	18-3649 (12)	18-2552 (2)		18-3648
215 FORD	2781153 - 3040410	18-3551
215 FORD	3040411 - UP	18-3551	18-2834		18-3651
215 FORD MCM	3040411 - 3385720	18-3649	18-2834		18-3646
215 FORD MIE	3040411 - 3385720	18-3649	18-2834		18-3646
225 GM	1539620 - 2278646	18-3551
225 GM	2278647 - 2399197	18-3551	18-2552 (2)		18-3668
225 GM	2399198 - 2694014	18-3551	18-2553 (3)		18-3651
225	3385721 - UP	18-3551	18-2834		18-3651
225S FORD	3385721 - UP	18-3551	18-2834		18-3651
225 FORD MCM	3385721 - 4176999	18-3649	18-2834		18-3646
225 FORD MIE	3385721 - 4176999	18-3649	18-2834		18-3646
228 GM	4765100 - 6218461	18-3551	18-2844	18-1993	18-3651
228 GM MCM	4765100 - 6218461	18-3649	18-2844 (4)		18-3646
228 GM MIE	4765100 - 6218461	18-3649	18-2844 (4)		18-3646
228 GM	6218462 - B525981	18-3551	18-2553 (1)	18-1994 (14)	18-3668
230 GM	6218462 - B525981	18-3551	18-2553 (1)	18-1994 (14)	18-3668
230 GM IB (10)	5907058 - B522505	18-3551	18-2553 (1)		18-3668
230 GM IB (11)	5907058 - B522505	18-3551	18-2553 (3)		18-3651
230 MIE	5907058 - B522505	18-3649	18-2553 (3,4)		18-3646
230(10,8)	B522506 - B525981	18-3551	18-2553		18-3668
230(10,9)	B522506 - B525981	18-3649 (12)	18-2552 (2)		18-3648
230(9)	B522506 - B525981	18-3649 (12)	18-2552 (2)		18-3648
230(11)	B522506 - B525981	18-3551	18-2553 (3)		18-3651
230	B522506 - B788151	18-3649	18-2553 (3,4)		18-3646
230(8)	B525982 - F600999	18-3551	18-2553 (1)	18-1994 (14)	18-3668
230	B525982 - F600999	18-3649 (12)	18-2552 (2)	18-1994 (14)	18-3648
230	B525982 - F600999	18-3649	18-2917		18-3647
230(9)	B525982 - UP	18-3551	18-2552 (2)		18-3668
233 FORD	4173000 - UP	18-3551	18-2834		18-3651
233 FORD MIE	4173000 - 4902304	18-3649	18-2834		18-3646
250 GM	2314301 - 2639854	18-3551	18-2553 (3)		18-3651
250 GM MIE	2314301 - 2639854	18-3649	18-2533 (3,4)		18-3646
250 GM MCM	2314301 - 2639854	18-3649	18-2533 (3,4)		18-3646
250 GM MCM	4175500 - 5907057	18-3649	18-2844 (4)		18-3646
250 GM MIE	4175500 - 5907057	18-3649	18-2844 (4)		18-3646
250 GM	4768000 - 4908849	18-3551	18-2844	18-1993	18-3651
250 GM	4768000 - 4908849	18-3649	18-2844 (4)		18-3646
255 FORD MCM	3258728 - 4178299	18-3649	18-2834		18-3646
255 FORD MIE	3258728 - 4178299	18-3649	18-2834		18-3646
255 GM	4175500 - 4767999	18-3551	18-2844	18-1993	18-3651
255 FORD	3258728 - UP	18-3551	18-2834		18-3651
260 GM	4908850 - 6218461	18-3551	18-2844		18-3651
260 GM	4908850 - 6218461	18-3649	18-2844 (4)		18-3646
260 GM IB (10)	5907058 - B522505	18-3551	18-2553 (1)		18-3668
260 GM IB (11)	5907058 - B522505	18-3551	18-2553 (3)		18-3651
260 MIE	5907058 - B522505	18-3649	18-2553 (3,4)		18-3646
260 GM	6218462 - B525981	18-3551	18-2553 (1)	18-1994 (14)	18-3668
260(10,8)	B522506 - B525981	18-3551	18-2553 (1)		18-3668
260(10,9)	B522506 - B525981	18-3551	18-2552 (2)		18-3668
260(11)	B522506 - B525981	18-3551	18-2553 (3)		18-3651
260 (10,9)	B522506 - B525981	18-3649 (12)	18-2552 (2)		18-3648
260(8)	B525982 - F600999	18-3551	18-2553 (1)	18-1994 (14)	18-3668
260(9)	B525982 - F600999	18-3551	18-2552 (2)		18-3668
260(9)	B525982 - F600999	18-3649 (12)	18-2552 (2)		18-3648
260	B525982 - F600999	18-3649	18-2917		18-3647
260	B522506 - F024999	18-3649	18-2553 (3,4)		18-3646
262 MAG ALPHA	F803800 - K999999	18-3649	18-2917		18-3647
262 MAG BRAVO	F803800 - K999999	18-3649	18-2917		18-3647
270 GM	2851074 - 3077735	18-3551	18-2553 (3)		18-3651
270 GM MCM	2851074 - 3385720	18-3649	18-2553 (3,4)		18-3646
270 GM MIE	2851074 - 3385720	18-3649	18-2553 (3,4)		18-3646
280 GM	4176250 - 4770199	18-3649	18-2844 (4)		18-3646
280 GM TRS	4176250 - 4770199	18-3551	18-2844	18-1993	18-3651
300 MR GM	6668677 - B430367	18-3551	18-2553 (1)	18-1994 (14)	18-3668
300 TRS GM	6668677 - B430367	18-3551	18-2553 (1)	18-1994 (14)	18-3668
320 GM	A543604 - C622418	18-3649	18-2553 (3,4)		18-3646
320 GM EFI	A543604 - UP	18-3551	18-2553 (3)		18-3651
325 GM	2278747 - 2313964	18-3551	18-2553		18-3668
325 GM MCM	2278747 - 3780449	18-3649	18-2553 (3,4)		18-3646
325 GM MIE	2278747 - 3780449	18-3649	18-2553 (3,4)		18-3646
325 GM	2313965 - 3042730	18-3551	18-2553 (3)		18-3651
325 GM	3042731 - UP	18-3551	18-2844		18-3651
330 GM	4623115 - UP	18-3551	18-2844		18-3651
330 GM MCM	4623115 - B816540	18-3649	18-2553 (3,4)		18-3646
330 GM MIE	4623115 - B816540	18-3649	18-2553 (3,4)		18-3646
330 GM W/BW (10)	6083145 - UP	18-3551	18-2553 (1)		18-3668
330 GM W/BW (11)	6083145 - UP	18-3551	18-2553 (3)		18-3651
340 GM IB (10,8)	5889914 - UP	18-3551	18-2553 (1)		18-3668
340 GM IB (10,9)	5889914 - UP	18-3551	18-2552 (2)		18-3668
340 GM IB (11)	5889914 - UP	18-3551	18-2553 (3)		18-3651
340 MIE	5889914 - D715493	18-3649	18-2553 (3,4)		18-3646
350 MIE	3780450 - 4623109	18-3649	18-2844 (4)		18-3646
350 GM	3780450 - UP	18-3551	18-2844		18-3651
350 MAG	B525982 - F600999	18-3551	18-2552 (2)	18-1994 (14)	18-3668
350 MAG GM	A635178 - B525981	18-3551	18-2553 (1)		18-3668
350 MAG GM(8)	B525982 - UP	18-3551	18-2553 (1)		18-3668
350 MAG GM(9)	B525982 - UP	18-3551	18-2552 (2)		18-3668
350 MAG GM(9)	B525982 - UP	18-3649 (12)	18-2552 (2)		18-3648
350 MAG	B252882 - K999999	18-3649	18-2917		18-3647
350 MAG	B252882 - K999999	18-3649	18-2917		18-3647
350 MAG SKI	D505450 - K999999	18-3649	18-2917		18-3647
350 MAG EFI SKI	F215561 - K999999	18-3649	18-2917		18-3647
350 MAG MPI SKI	F350583 - UP	18-3649	18-2917		18-3647
350 MAG MIE	L010019 - UP	18-3649	18-2917		18-3647
350 MAG MPI	L010019 - UP	18-3649	18-2917		18-3647
370 GM	4179554 - 6721527	18-3649	18-2553 (3,4)		18-3646
370 TRS GM	4179554 - 6721527	18-3551	18-2553 (3)		18-3651
370 TRS GM	6721528 - UP	18-3551	18-2553 (1)		18-3668
390 GM	2781129 - 2825059	18-3551	18-2553 (3)		18-3651
390 GM MCM	2781129 - 3042731	18-3649	18-2553 (3,4)		18-3646
390 GM MIE	2781129 - 3042731	18-3649	18-2553 (3,4)		18-3646
400 GM	4179554 - B457644	18-3649	18-2553 (3,4)		18-3646
400 TRS GM	4179554 - UP	18-3551	18-2553 (3)		18-3651
420 GM	A398941 - B622418	18-3649	18-2553 (3,4)		18-3646
420 GM	A398941 - UP	18-3551	18-2553 (3)		18-3651
440 TRS GM	4179554 - UP	18-3551	18-2553 (3)		18-3651
454 GM MAGNUM ALPHA (8)	A631894 - B785148	18-3551	18-2553 (1)		18-3668
454 GM MAGNUM BRAVO (9)	A631894 - UP	18-3551	18-2552 (2)		18-3668
454 GM MAGNUM BRAVO (9)	B721206 - UP	18-3649 (12)	18-2552 (2)		18-3648
454 MAG MCM	F305000 - K999999	18-3649	18-2917		18-3647
454 MAG SKI	F305000 - K999999	18-3649	18-2917		18-3647
460 TRS GM	4179554 - UP	18-3551	18-2553 (3)		18-3651
470	4208730 - 6218036	18-3552	18-2843		18-3652
470	6218037 - UP	18-3555	18-2555		18-3667
485	5685394 - UP	18-3552	18-2555		18-3652
488	6170297 - UP	18-3555	18-2555		18-3667
500 (Gen V)	F213293 - F615766	18-3551	18-2844	18-1994 (14)	18-3651
502 EFI MCM	F8026000 - K999999	18-3649	18-2917		18-3647
502 MAG MPI	L017000 - UP	18-3649	18-2917		18-3647
502 MPI MCM	F8026000 - K999999	18-3649	18-2917		18-3647
575 GM	A677429 - D763716	18-3649	18-2553 (3,5)		18-3646
575	A677429 - UP	18-3551	18-2553 (3)		18-3651
888 FORD	3108723 - UP	18-3551	18-2834		18-3651
888 FORD MCM	3108723 - 4887829	18-3649	18-2834		18-3646
898 GM	4762210 - 6218461	18-3551	18-2844		18-3651
898 GM MCM	4762210 - 6218461	18-3649	18-2844 (4)		18-3646
898 GM MIE	4762210 - 6218461	18-3649	18-2844 (4)		18-3646
898 GM	6218462 - UP	18-3551	18-2553 (1)		18-3668
2.5L (7)	2324347 - UP	18-3550	18-2831		18-3650
3.0L	2508261 - UP	18-3550	18-2831		18-3650 (13)
3.0L	C856559 - UP	18-3550	18-2831		18-3650
3.0LX	C856559 - UP	18-3550	18-2831		18-3650
3.7L (4 CYL)	6916779 - UP	18-3555	18-2555		18-3667
3.7L (4 CYL)	6916779 - UP	18-3555	18-2555		18-3667
3.7LX (4 CYL)	6916779 - UP	18-3555	18-2555		18-3667
4.3L (262 CID) (8)	B527955 - D714369	18-3551	18-2553 (1)	18-1994 (14)	18-3668
4.3L (262 CID) (9)	B527955 - D714369	18-3551	18-2552 (2)		18-3668
4.3L(8)	B527955 - UP	18-3551	18-2553 (1)		18-3668
4.3L(9)	B527955 - UP	18-3551	18-2552 (2)		18-3668
4.3L GM	F000878 - F601126	18-3649	18-2917		18-3647
4.3L (262 CID) (9)	F001220 - UP	18-3649 (12)	18-2552 (2)		18-3648
4.3L(9)	F001220 - UP	18-3649 (12)	18-2552 (2)		18-3648
4.3L ALPHA	F601127 - K999999	18-3649	18-2917		18-3647
4.3L BRAVO	F601127 - K999999	18-3649	18-2917		18-3647
4.3L	L010044 - UP	18-3649	18-2917		18-3647
4.3L ALPHA	L010044 - UP	18-3649	18-2917		18-3647
4.3L EFI	L010044 - UP	18-3649	18-2917		18-3647
4.3L EFI ALPHA	L010044 - UP	18-3649	18-2917		18-3647
4.3LH	L010044 - UP	18-3649	18-2917		18-3647
4.3LH ALPHA	L010044 - UP	18-3649	18-2917		18-3647
4.3LX (262 CID) (8)	B527955 - D714369	18-3551	18-2553 (1)	18-1994 (14)	18-3668
4.3LX (262 CID) (9)	B527955 - D714369	18-3551	18-2552 (2)		18-3668
4.3LX (262 CID) (8)	B527955 - UP	18-3551	18-2553 (1)		18-3668
4.3LX (262 CID) (9)	B527955 - UP	18-3551	18-2552 (2)		18-3668
4.3LX GM	F000878 - F601126	18-3649	18-2917		18-3647
4.3LX (262 CID) (9)	F001220 - UP	18-3649 (12)	18-2552 (2)		18-3648
4.3LX (262 CID) (9)	F001220 - UP	18-3649 (12)	18-2552 (2)		18-3648
4.3LX ALPHA	F601127 - K999999	18-3649	18-2917		18-3647
4.3LX BRAVO	F601127 - K999999	18-3649	18-2917		18-3647
4.3LXH ALPHA	F601127 - K999999	18-3649	18-2917		18-3647
4.3LXH BRAVO	F601127 - K999999	18-3649	18-2917		18-3647
5.0L GM IB (10,8)	B522506 - B525981	18-3551	18-2553		18-3668
5.0L GM IB (10,9)	B522506 - B525981	18-3649 (12)	18-2552 (2)		18-3648
5.0L GM IB (11)	B522506 - B525981	18-3551	18-2553 (3)		18-3651
5.0L GM IB (9)	B522506 - B525981	18-3649 (12)	18-2552 (2)		18-3648
5.0L MIE	B522506 - B788151	18-3649	18-2553 (3,4)		18-3646
5.0L	B525982 - F600999	18-3649	18-2917		18-3647
5.0L GM (8)	B525982 - F600999	18-3551	18-2553 (1)	18-1994 (14)	18-3668
5.0L GM	B525982 - F600999	18-3649 (12)	18-2552 (2)	18-1994 (14)	18-3648
5.0L GM (8)	B525982 - UP	18-3551	18-2553 (1)	18-1994 (14)	18-3668
5.0L GM (9)	B525982 - UP	18-3649 (12)	18-2552 (2)	18-1994 (14)	18-3648
5.0L GM (9)	B525982 - UP	18-3551	18-2552 (2)		18-3668
5.0L ALPHA	L012052 - UP	18-3649	18-2917		18-3647
5.0L BRAVO	L012052 - UP	18-3649	18-2917		18-3647
5.0L EFI ALPHA	L012052 - UP	18-3649	18-2917		18-3647
5.0L EFI BRAVO	L012052 - UP	18-3649	18-2917		18-3647
5.0LX GM (8)	B525982 - F600999	18-3551	18-2553 (1)	18-1994 (14)	18-3668
5.0LX GM	B525982 - F600999	18-3649 (12)	18-2552 (2)	18-1994 (14)	18-3648
5.0LX GM	B525982 - F600999	18-3649	18-2917		18-3647
5.0LX GM (9)	B525982 - UP	18-3551	18-2552 (2)		18-3668
5.7L SKI GM	A338553 - B514626	18-3551	18-2553 (1)	18-1994 (14)	18-3668
5.7L SKI	B514627 - UP	18-3649	18-2917		18-3647
5.7L SKI BRAVO (8)	B514627 - UP	18-3551	18-2553 (1)		18-3668
5.7L SKI BRAVO (9)	B514627 - UP	18-3551	18-2552 (2)		18-3668
5.7L SKI BRAVO (9)	B514627 - UP	18-3649 (12)	18-2552 (2)		18-3648
5.7L GM IB (10,8)	B522506 - B525981	18-3551	18-2553 (1)		18-3668
5.7L GM IB (10,9)	B522506 - B525981	18-3551	18-2552 (2)		18-3668
5.7L GM IB (10,9)	B522506 - B525981	18-3649 (12)	18-2552 (2)		18-3648
5.7L GM IB (11)	B522506 - B525981	18-3551	18-2553 (3)		18-3651
5.7L MIE	B522506 - F024999	18-3649	18-2553 (3,4)		18-3646
5.7L GM (8)	B525982 - F600999	18-3551	18-2553 (1)	18-1994 (14)	18-3668
5.7L GM (9)	B525982 - F600999	18-3551	18-2552 (2)		18-3668
5.7L GM (9)	B525982 - F600999	18-3649 (12)	18-2552 (2)		18-3648
5.7L GM	B525982 - F600999	18-3649	18-2917		18-3647
5.7L MIE	F025000 - F622099	18-3649	18-2844		18-3647
5.7L GM ALPHA	F225560 - K999999	18-3649	18-2917		18-3647
5.7L GM BRAVO	F225560 - K999999	18-3649	18-2917		18-3647
5.7L MIE	F622100 - K999999	18-3649	18-2917		18-3647
5.7L MIE	F622100 - K999999	18-3649	18-2844		18-3647
5.7L MIE	L002003 - UP	18-3649	18-2917		18-3647
5.7L EFI GM ALPHA	L010037 - UP	18-3649	18-2917		18-3647
5.7L EFI GM BRAVO	L010037 - UP	18-3649	18-2917		18-3647
5.7L GM ALPHA	L010037 - UP	18-3649	18-2917		18-3647
5.7L GM BRAVO	L010037 - UP	18-3649	18-2917		18-3647
7.4L MIE	5889914 - D715493	18-3649	18-2553 (3,4)		18-3646
7.4L GM IB (10,8)	5889914 - UP	18-3551	18-2553 (1)		18-3668
7.4L GM IB (10,9)	5889914 - UP	18-3551	18-2552 (2)		18-3668
7.4L GM IB (11)	5889914 - UP	18-3551	18-2553 (3)		18-3651
7.4L BRAVO GM (8)	B771113 - D603117	18-3551	18-2553 (1)		18-3668
7.4L BRAVO GM (9)	B771113 - UP	18-3551	18-2552 (2)		18-3668
7.4L MIE	C391564 - D715493	18-3649	18-2553 (3,4)		18-3646
7.4L W/HURTH IB (10)	C391564 - D715493	18-3551	18-2552 (2)		18-3668
7.4L MIE	C391564 - F349999	18-3649	18-2553 (3,4)		18-3646
7.4L W/HURTH IB (11)	C391564 - UP	18-3551	18-2553 (3)		18-3651
7.4L BRAVO GM (9)	D603118 - UP	18-3649 (12)	18-2552 (2)		18-3648
7.4L MIE	D715494 - F820141	18-3649	18-2553 (3,4)		18-3646
7.4L W/HURTH IB	D715494 - UP	18-3649 (12)	18-2553 (3)		18-3648
7.4L GM	F352000 - K999999	18-3649	18-2917		18-3647
7.4LX GM	F352000 - K999999	18-3649	18-2917		18-3647
7.4L MPI	F563052 - UP	18-3649	18-2917		18-3647
7.4L TBI	F563052 - UP	18-3649	18-2917		18-3647
7.4L MIE	F820142 - K999999	18-3649	18-2917		18-3647
7.4L MIE	F820142 - K999999	18-3649	18-2844 (4)		18-3647
8.2L MIE	D857200 - F350274	18-3649	18-2917		18-3647
8.2L MIE	D857200 - F819619	18-3649	18-2844 (4)		18-3647
8.2L MIE	F350275 - F819619	18-3649	18-2917		18-3647
8.2L MIE	F819620 - UP	18-3649	18-2917		18-3647
8.2L MPI	F819620 - UP	18-3649	18-2917		18-3647
ROVER	3140000 - UP	18-3551
SCORPION SKI	F800000 - UP	18-3649	18-2917		18-3647
Engine Model	Serial Range	Thermostat	Gaskets	Housing	Thermostat Kit

Notes: (1) : Also Requires Gasket 18-2554 (2) : Also Requires Gasket 18-7173 (3) : Also Requires Gasket 18-2844 (4) : Also Requires Gasket 18-2917 (5) : Also Requires Gasket 18-2914 (6) : Aluminum Manifold (7) : Cast Iron (8) : Old Design (9) : New Design (10) : Std. Cooling (11) : Closed Cooling (12) : 160 Degree (13) : S/N 6229718 & up (14) : For stainless steel version use 18-1989