Fan Shroud/fan Clutch - The 1947 - Present Chevrolet & GMC Truck Message Board Network

72LNGHRN · 08-30-2002, 03:20 AM

DOES ANYBODY KNOW WHAT THE DIFFERENCE BETWEEN A SMALL BLOCK FAN SHROUD AND A BIG BLOCK FAN SHROUD? ALSO I NEED TO KNOW WHAT THE DISTANCE IS ON A SMALL BLOCK TRUCK BETWEEN THE FRONT OF THE FAN CLUTCH AND THE RADIATOR THANKS IN ADVANCE

72LNGHRN · 09-01-2002, 12:19 AM

ttt

BubbaGreen · 09-01-2002, 11:12 AM

Dont know about the distance, but the main difference between a big block shroud and a small block is the opening for the fan.
If I remember, the small block opening measures 19inches, where as, the big block measures 21inches. Most late model 350 engines come with a fan that is 19 to 19.5inches, so its too big to fit in the standard small block shrouds. ONe trick, is to use a fan from say a 1989 S-10 that had a 4.3L V6....that fan only measures 18.5" and will fit, although clearance is a bit tight.
If you go to the dealer and ask for more info, there are different part numbers for the thermal clutches. The 350 has a standard one, or a heavy duty one, and I think even another if the rear end ratio is a 3.73. The 4.3L s-10 fan will bolt right up to any of the 350 clutches. But if you want to use a 350 fan/clutch, you will need to get a big block shroud....or if you can find one, a shroud that came from a gmc with a 305 V6 works perfect. This is what i went with.
Either way. good luck!

08-30-2002, 03:20 AM	#1
72LNGHRN Registered User Join Date: Mar 2000 Location: Tucson AZ USA Posts: 241	Fan Shroud/fan Clutch DOES ANYBODY KNOW WHAT THE DIFFERENCE BETWEEN A SMALL BLOCK FAN SHROUD AND A BIG BLOCK FAN SHROUD? ALSO I NEED TO KNOW WHAT THE DISTANCE IS ON A SMALL BLOCK TRUCK BETWEEN THE FRONT OF THE FAN CLUTCH AND THE RADIATOR THANKS IN ADVANCE __________________ 72LONGHORN 350 CI TURBO 400 A/C P/S P/B HEAVY DUTY SPRINGS ALL THE BELLS AND WHISTLES. TUCSON,AZ. 2005 4X4 DODGE RAM 1500 "HEMI"LARAMIE 1961 OLDS DYNAMIC 88 394 4BBL UNDER CONST.

09-01-2002, 12:19 AM	#2
72LNGHRN Registered User Join Date: Mar 2000 Location: Tucson AZ USA Posts: 241	ttt __________________ 72LONGHORN 350 CI TURBO 400 A/C P/S P/B HEAVY DUTY SPRINGS ALL THE BELLS AND WHISTLES. TUCSON,AZ. 2005 4X4 DODGE RAM 1500 "HEMI"LARAMIE 1961 OLDS DYNAMIC 88 394 4BBL UNDER CONST.

09-01-2002, 11:12 AM	#3
BubbaGreen Senior Member Join Date: Mar 2001 Location: Cedar Park, TX Posts: 686	Dont know about the distance, but the main difference between a big block shroud and a small block is the opening for the fan. If I remember, the small block opening measures 19inches, where as, the big block measures 21inches. Most late model 350 engines come with a fan that is 19 to 19.5inches, so its too big to fit in the standard small block shrouds. ONe trick, is to use a fan from say a 1989 S-10 that had a 4.3L V6....that fan only measures 18.5" and will fit, although clearance is a bit tight. If you go to the dealer and ask for more info, there are different part numbers for the thermal clutches. The 350 has a standard one, or a heavy duty one, and I think even another if the rear end ratio is a 3.73. The 4.3L s-10 fan will bolt right up to any of the 350 clutches. But if you want to use a 350 fan/clutch, you will need to get a big block shroud....or if you can find one, a shroud that came from a gmc with a 305 V6 works perfect. This is what i went with. Either way. good luck! __________________ 71 Chevy C-10 SWB Fleetside RamJet-350/4L60e & Compushift/3.73Posi See it at www.prismnet.com/~grzanich



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.