SM465 Clutch kit suggestions? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Chilly178 · 04-26-2018, 08:52 PM

Anyone have any suggestions on what brand/type of clutch kit to get for a 72 C20 350 with SM465? Pretty sure its a 11" clutch. Not sure weather to go ceramic or organic clutch disk, self aligning vs regular throw out bearing, etc. What do you guys use? Also anyone have a link/part number for a poly version of the rubber mount that the trans sits on the cross member? I already have the engine mounts I would just like to replace that mount. Thanks.

Mike C · 04-26-2018, 08:57 PM

IME, most SM465 clutches are 12". I would just buy a complete clutch kit off RockAuto. Most run about $100.

If you are lucky, you may score one on Clearance. I bought a complete one with a puck style metallic clutch for $40. :-)

**'68OrangeSunshine** · 04-26-2018, 09:16 PM

A '72 flywheel will be 12''. '71 and earlier will be 11''.
I used the Centerforce II clutch set up on both my '71 GMC Jimmy w/ V8 350/SM465/NP205, and also '68 C/10 w/ 292 L6/SM465.

Chilly178 · 04-26-2018, 09:49 PM

Oh okay. So this flywheel won't work with a 5.7 vortec and 12" clutch? https://www.summitracing.com/parts/n...8/applications

**'68OrangeSunshine** · 04-26-2018, 10:10 PM

If you don't have the original '72 12" flywheel, then I don't think the universe will come to a screeching halt if you used an 11". But I could be corrected. The SM465 didn't get a 12" flywheel til MY 1972. '68 thru '71 SM465s used the 11". I guess the 11.85" is called the "Twelve Inch."
If they're the same price get the bigger one.

palallin · 04-26-2018, 10:33 PM

My '69 SM 465 K-10 has a 12". I am pretty sure it came that way.

57taskforce · 04-27-2018, 12:27 AM

I got a 12” luk from NAPA for my K20. I was around $120 for everything except for machine work to my flywheel.

CastIron · 04-27-2018, 12:41 AM

I used a Luk clutch with my 3 speed. They are original equipment on a lot of GM cars and trucks. Which exact one for your application? I'm not sure, but I can't imagine there is too many different clutches for these old trucks. Probably only a couple of sizes?

BCOWANWHEELS · 04-27-2018, 01:22 AM

oreillys are lifetime guarantee for around 100.00. organic is oem and easyiest on flywheels. 12 in if it will fit but 11 h/d would be more than enough.

Chilly178 · 04-27-2018, 10:02 PM

I guess i'll have to tear the engine out and look at the clutch to see for myself. Seems like its either 11.85" or 12". It kinda matters because the flywheel I was looking at takes a 11.85 max. Steel or cast flywheel by the way?

Mike C · 04-27-2018, 10:23 PM

The OEM flywheel will be cast iron.

**'68OrangeSunshine** · 04-27-2018, 11:42 PM

Quote:

Originally Posted by Chilly178

I guess i'll have to tear the engine out and look at the clutch to see for myself. Seems like its either 11.85" or 12". It kinda matters because the flywheel I was looking at takes a 11.85 max. Steel or cast flywheel by the way?

I think the so-called 12" is actually 11.85" if measured exactly. But check with someone else. I'm not an expert.
Steel or cast-iron? IDK.

BCOWANWHEELS · 04-28-2018, 03:24 AM

no need to pull engine or trans............ just slide trans back about 8 inches. steel flywheel not needed. cast is fine in fact just resurface it. new pilot bushing and throwout brg. I don't think a 12 in will fit in our bellhsgs. 11 in is biggest. been a while. check clutch fork for wear............

57taskforce · 04-28-2018, 09:43 AM

Quote:

Originally Posted by BCOWANWHEELS

no need to pull engine or trans............ just slide trans back about 8 inches. steel flywheel not needed. cast is fine in fact just resurface it. new pilot bushing and throwout brg. I don't think a 12 in will fit in our bellhsgs. 11 in is biggest. been a while. check clutch fork for wear............

My 72 has a factory 12”

04-26-2018, 08:52 PM	#1
Chilly178 Registered User Join Date: May 2016 Location: Green Bay, WI Posts: 135	SM465 Clutch kit suggestions? Anyone have any suggestions on what brand/type of clutch kit to get for a 72 C20 350 with SM465? Pretty sure its a 11" clutch. Not sure weather to go ceramic or organic clutch disk, self aligning vs regular throw out bearing, etc. What do you guys use? Also anyone have a link/part number for a poly version of the rubber mount that the trans sits on the cross member? I already have the engine mounts I would just like to replace that mount. Thanks. Last edited by Chilly178; 04-26-2018 at 09:02 PM.

04-26-2018, 08:57 PM	#2
Mike C Registered User Join Date: Dec 1999 Location: Austin, TX, USA Posts: 7,727	Re: SM465 Clutch kit suggestions? IME, most SM465 clutches are 12". I would just buy a complete clutch kit off RockAuto. Most run about $100. If you are lucky, you may score one on Clearance. I bought a complete one with a puck style metallic clutch for $40. :-) __________________ 44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax

04-26-2018, 09:16 PM	#3
'68OrangeSunshine Senior Member Join Date: Feb 2002 Location: Tucson, AZ USA Posts: 7,504	Re: SM465 Clutch kit suggestions? A '72 flywheel will be 12''. '71 and earlier will be 11''. I used the Centerforce II clutch set up on both my '71 GMC Jimmy w/ V8 350/SM465/NP205, and also '68 C/10 w/ 292 L6/SM465. __________________ Every 25 years I like to rebuild that 292, whether it needs it or not.

04-26-2018, 09:49 PM	#4
Chilly178 Registered User Join Date: May 2016 Location: Green Bay, WI Posts: 135	Re: SM465 Clutch kit suggestions? Oh okay. So this flywheel won't work with a 5.7 vortec and 12" clutch? https://www.summitracing.com/parts/n...8/applications Last edited by Chilly178; 04-26-2018 at 10:10 PM.

04-26-2018, 10:10 PM	#5
'68OrangeSunshine Senior Member Join Date: Feb 2002 Location: Tucson, AZ USA Posts: 7,504	Re: SM465 Clutch kit suggestions? If you don't have the original '72 12" flywheel, then I don't think the universe will come to a screeching halt if you used an 11". But I could be corrected. The SM465 didn't get a 12" flywheel til MY 1972. '68 thru '71 SM465s used the 11". I guess the 11.85" is called the "Twelve Inch." If they're the same price get the bigger one. __________________ Every 25 years I like to rebuild that 292, whether it needs it or not.

04-26-2018, 10:33 PM	#6
palallin Registered User Join Date: Jul 2002 Location: St. James, MO Posts: 1,238	Re: SM465 Clutch kit suggestions? My '69 SM 465 K-10 has a 12". I am pretty sure it came that way. __________________ '69 Longstep K-10: 327/SM465/T-221/Closed Knuckle Dana44/12-bolt.

04-27-2018, 12:27 AM	#7
57taskforce All about them K’s Join Date: Jun 2014 Location: Land of Entrapment Posts: 6,487	Re: SM465 Clutch kit suggestions? I got a 12” luk from NAPA for my K20. I was around $120 for everything except for machine work to my flywheel. __________________ Tyler '57 3100 http://67-72chevytrucks.com/vboard/s...d.php?t=813888 '72 K20 Cheyenne: 5” lift, 35’s, front dana 60 blah blah blah… http://67-72chevytrucks.com/vboard/s...d.php?t=662879 ‘69 K10 SWB: 4” lift 33”s… in a million pieces http://67-72chevytrucks.com/vboard/s...d.php?t=805206 '98 Silverado LT K2500HD ECLB Vortec 454/4l80E: 6" lift 35x12.5x20’s

04-27-2018, 12:41 AM	#8
CastIron Registered User Join Date: May 2013 Location: Oregon Posts: 329	Re: SM465 Clutch kit suggestions? I used a Luk clutch with my 3 speed. They are original equipment on a lot of GM cars and trucks. Which exact one for your application? I'm not sure, but I can't imagine there is too many different clutches for these old trucks. Probably only a couple of sizes?

04-27-2018, 01:22 AM	#9
BCOWANWHEELS Registered User Join Date: Nov 2006 Location: KINGSPORT,TN. Posts: 3,035	Re: SM465 Clutch kit suggestions? oreillys are lifetime guarantee for around 100.00. organic is oem and easyiest on flywheels. 12 in if it will fit but 11 h/d would be more than enough. __________________ I BELIEVE IN JOHN 3:16

04-27-2018, 10:02 PM	#10
Chilly178 Registered User Join Date: May 2016 Location: Green Bay, WI Posts: 135	Re: SM465 Clutch kit suggestions? I guess i'll have to tear the engine out and look at the clutch to see for myself. Seems like its either 11.85" or 12". It kinda matters because the flywheel I was looking at takes a 11.85 max. Steel or cast flywheel by the way?

04-27-2018, 10:23 PM	#11
Mike C Registered User Join Date: Dec 1999 Location: Austin, TX, USA Posts: 7,727	Re: SM465 Clutch kit suggestions? The OEM flywheel will be cast iron. __________________ 44 Willys MB 52 M38A1 64 Corvette Coupe 68 Camaro 'vert LT1 & TH700 69 Z/28 355 12.6's @110 69 Chevy Short Step 4 1/2"/7" drop 72 Jimmy 4WD 4spd 4" & 35's 02 GMC 2500HD 4x4 Duramax

04-28-2018, 03:24 AM	#13
BCOWANWHEELS Registered User Join Date: Nov 2006 Location: KINGSPORT,TN. Posts: 3,035	Re: SM465 Clutch kit suggestions? no need to pull engine or trans............ just slide trans back about 8 inches. steel flywheel not needed. cast is fine in fact just resurface it. new pilot bushing and throwout brg. I don't think a 12 in will fit in our bellhsgs. 11 in is biggest. been a while. check clutch fork for wear............ __________________ I BELIEVE IN JOHN 3:16



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