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

72LNGHRN · 05-14-2003, 01:08 PM

Does anybody know what the difference is between a small block fan shroud and a big block fan shroud? My truck was originally a big block truck converted to small block. Everything seems to be in the right spot but the only part of the fan that is in the shroud is the front of the clutch any help would be appreciated.

**CPNE** · 05-14-2003, 01:41 PM

Sounds like you have the BB shroud. Here is a pic of the OE small block ne. It is quite different than a BB.

cruzn72 · 05-14-2003, 04:06 PM

I have a SB shroud that I am using with my 350 and the fan barely goes inside of it. I was told to space the fan out using a longer fan mount.

**COBALT** · 05-14-2003, 04:09 PM

Yeah, that's a good idea. Summit Racing sells fan spacers, new fans, and water pump pulleys for getting your fand out there.

I have a newer 350 ('80), so it has a long water pump. I've debated about getting rid of that long water pump, and going with something a little easier to find pulleys, fans, and stuff for. Problem is I'd have to add a spacer!

Also, I really have to be careful about my shroud. The fan wants to hit it on the inside top really bad. I immediately knew when my motor mounts were bad because the fan would beat the crap out of the shroud...

Rod · 05-14-2003, 04:25 PM

BB fan shroud

Rod · 05-14-2003, 04:31 PM

Fan shroud SB V8 no ac

Rod · 05-14-2003, 04:35 PM

Fan shroud V8 small block for 4x4

**COBALT** · 05-14-2003, 04:44 PM

Yeah, that's a good idea. Summit Racing sells fan spacers, new fans, and water pump pulleys for getting your fand out there.

I have a newer 350 ('80), so it has a long water pump. I've debated about getting rid of that long water pump, and going with something a little easier to find pulleys, fans, and stuff for. Problem is I'd have to add a spacer!

Also, I really have to be careful about my shroud. The fan wants to hit it on the inside top really bad. I immediately knew when my motor mounts were bad because the fan would beat the crap out of the shroud...

Blue68 · 05-14-2003, 05:14 PM

The difference is a couple of inches. 17 vs. 19 I think. Other than that, they expect the fact center to be the same, but the small block is deeper too. I have pics of my engine (SB) with a big block fan in the link in my sig.

crazy longhorn · 05-14-2003, 05:18 PM

Im not sure I would add a spacer to a clutch fan, as there is some weight on the fan, & it can take a toll on the waterpump & or remove the hub from the waterpump(fan, pulley,spacer & all). I have seen that happen, & the rad didnt look to pretty after that. You can gain a little lenght by going to the 73 up style pump & pulleys/brackets. I run in I6 position, with the later (long )pump, & a 1 1/2" spacer to put the fan in the proper location......the fan is a very lite PLASTIC flex fan, to keep the weight off the pump hub. The BB also sets in a different position than the sb(if original mounts /stands), & that may be where the diff is. i would swap the shroud or pump/ pulleys to gain the distance& still keep the clutch fan. Goodluck,crazyL

72LNGHRN · 05-15-2003, 11:57 AM

Thanks for all the help.I had thought of using a spacer but thats alot of weight on the pump bearings.By the looks of the pictures the small block shroud should help alot.

Rod · 05-16-2003, 01:27 AM

a sb shroud on ebay http://cgi.ebay.com/ebaymotors/ws/eB...tem=2415636721

05-14-2003, 01:08 PM	#1
72LNGHRN Registered User Join Date: Mar 2000 Location: Tucson AZ USA Posts: 241	Fan Shroud Does anybody know what the difference is between a small block fan shroud and a big block fan shroud? My truck was originally a big block truck converted to small block. Everything seems to be in the right spot but the only part of the fan that is in the shroud is the front of the clutch any help would be appreciated. __________________ 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.

05-14-2003, 01:41 PM	#2
CPNE Resident Curmudgeon Join Date: Dec 1999 Location: NH Posts: 6,664	Sounds like you have the BB shroud. Here is a pic of the OE small block ne. It is quite different than a BB. Attached Images __________________ Currently on or near the homestead: 67 Chevy SWB 2WD stepside 350/3 on tree (Pat's) 67 GMC SWB 2WD Fleet 402/auto (Brian's under construction) 67 Chevy 3/4 ton 2WD 402/auto (Business Hauler) 67 Chevy 1 ton dually 2WD 396/4 speed (Former business hauler, Needs TLC) 68 Chevy 1/2 ton Suburban 2WD 250 six/3 on tree (Brian's Needs TLC) 70 Chevy 3/4 ton 4WD 350/4 speed (Pat's - Disguised as a 68 GMC) 71 Chevy SWB stepside (Crushed by tree - parts donor) 72 Chevy 3/4 ton 4WD (Parts donor) 72 Chevy 3/4 ton 4WD Suburban (Parts Donor) 72 GMC 3/4 ton 4WD 292 six/4 speed (Mine - Disguised as a 67 GMC) 81 GMC 4WD Dually Dump Body 350/4 speed (Business Hauler) 82 Camaro Z/28 355/Super T-10 (Pat's toy) 93 Caprice 9C1 (Brian's Cop Car) 02 Toyota Camry (Reliable but a souless steel and plastic hulk) 2011 2SS RS Camaro M6 Factory Hurst Shifter Maybe I need to sell some of this crap Yet another Bozo with a sawz-all

05-14-2003, 04:06 PM	#3
cruzn72 Registered User Join Date: Mar 2003 Posts: 99	I have a SB shroud that I am using with my 350 and the fan barely goes inside of it. I was told to space the fan out using a longer fan mount. __________________ http://photos.yahoo.com/cruzn72@pacbell.net

05-14-2003, 04:09 PM	#4
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	Yeah, that's a good idea. Summit Racing sells fan spacers, new fans, and water pump pulleys for getting your fand out there. I have a newer 350 ('80), so it has a long water pump. I've debated about getting rid of that long water pump, and going with something a little easier to find pulleys, fans, and stuff for. Problem is I'd have to add a spacer! Also, I really have to be careful about my shroud. The fan wants to hit it on the inside top really bad. I immediately knew when my motor mounts were bad because the fan would beat the crap out of the shroud... __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA.

05-14-2003, 04:25 PM	#5
Rod Join Date: Dec 1999 Location: Eastern - Manitoba Canada, Winnipeg Posts: 4,369	BB fan shroud Attached Images __________________ Senior active founding member. 70 3/4 ton GMC Suburban 4x4 250/4 spd. 71 1/2 ton Suburban Chevy 4x4, 350/350 72 Chev 1 ton tow truck 402BB w/Holmes 440 wrecker on propane 2005 FLSTSCI Harley Springer 85 FXSB Harley Lowrider 72 Triumph 650 Bonneville 5spd "Poor people don't have hobbies" Quote from wife.

05-14-2003, 04:31 PM	#6
Rod Join Date: Dec 1999 Location: Eastern - Manitoba Canada, Winnipeg Posts: 4,369	Fan shroud SB V8 no ac Attached Images __________________ Senior active founding member. 70 3/4 ton GMC Suburban 4x4 250/4 spd. 71 1/2 ton Suburban Chevy 4x4, 350/350 72 Chev 1 ton tow truck 402BB w/Holmes 440 wrecker on propane 2005 FLSTSCI Harley Springer 85 FXSB Harley Lowrider 72 Triumph 650 Bonneville 5spd "Poor people don't have hobbies" Quote from wife.

05-14-2003, 04:35 PM	#7
Rod Join Date: Dec 1999 Location: Eastern - Manitoba Canada, Winnipeg Posts: 4,369	Fan shroud V8 small block for 4x4 Attached Images __________________ Senior active founding member. 70 3/4 ton GMC Suburban 4x4 250/4 spd. 71 1/2 ton Suburban Chevy 4x4, 350/350 72 Chev 1 ton tow truck 402BB w/Holmes 440 wrecker on propane 2005 FLSTSCI Harley Springer 85 FXSB Harley Lowrider 72 Triumph 650 Bonneville 5spd "Poor people don't have hobbies" Quote from wife.

05-14-2003, 04:44 PM	#8
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	Yeah, that's a good idea. Summit Racing sells fan spacers, new fans, and water pump pulleys for getting your fand out there. I have a newer 350 ('80), so it has a long water pump. I've debated about getting rid of that long water pump, and going with something a little easier to find pulleys, fans, and stuff for. Problem is I'd have to add a spacer! Also, I really have to be careful about my shroud. The fan wants to hit it on the inside top really bad. I immediately knew when my motor mounts were bad because the fan would beat the crap out of the shroud... __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA.

05-14-2003, 05:14 PM	#9
Blue68 Registered User Join Date: Apr 2000 Location: Frisco, Tx, USA Posts: 606	The difference is a couple of inches. 17 vs. 19 I think. Other than that, they expect the fact center to be the same, but the small block is deeper too. I have pics of my engine (SB) with a big block fan in the link in my sig. __________________ http://home.comcast.net/~r.landrum/w...tos.html-.html '68 C-10 LWB, '98 Z-71 350 w/accessories (Serpentine), Edelbrock Performer, Edelbrock 1405 (600cfm) carb, GM HEI, CompCam Extreme 4x4 roller cam, Thorley Headers, Carter Electric Fuel Pump, Vintage Air, 700r4, 3.73, disc brakes and power steering upgrades.

05-14-2003, 05:18 PM	#10
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,403	Im not sure I would add a spacer to a clutch fan, as there is some weight on the fan, & it can take a toll on the waterpump & or remove the hub from the waterpump(fan, pulley,spacer & all). I have seen that happen, & the rad didnt look to pretty after that. You can gain a little lenght by going to the 73 up style pump & pulleys/brackets. I run in I6 position, with the later (long )pump, & a 1 1/2" spacer to put the fan in the proper location......the fan is a very lite PLASTIC flex fan, to keep the weight off the pump hub. The BB also sets in a different position than the sb(if original mounts /stands), & that may be where the diff is. i would swap the shroud or pump/ pulleys to gain the distance& still keep the clutch fan. Goodluck,crazyL __________________ 69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears....

05-15-2003, 11:57 AM	#11
72LNGHRN Registered User Join Date: Mar 2000 Location: Tucson AZ USA Posts: 241	Thanks for all the help.I had thought of using a spacer but thats alot of weight on the pump bearings.By the looks of the pictures the small block shroud should help alot. __________________ 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.

05-16-2003, 01:27 AM	#12
Rod Join Date: Dec 1999 Location: Eastern - Manitoba Canada, Winnipeg Posts: 4,369	a sb shroud on ebay http://cgi.ebay.com/ebaymotors/ws/eB...tem=2415636721 __________________ Senior active founding member. 70 3/4 ton GMC Suburban 4x4 250/4 spd. 71 1/2 ton Suburban Chevy 4x4, 350/350 72 Chev 1 ton tow truck 402BB w/Holmes 440 wrecker on propane 2005 FLSTSCI Harley Springer 85 FXSB Harley Lowrider 72 Triumph 650 Bonneville 5spd "Poor people don't have hobbies" Quote from wife.



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.