clutch questions - The 1947 - Present Chevrolet & GMC Truck Message Board Network

powerline84 · 11-01-2008, 11:28 AM

Since i am putting a new crate motor in thats considerably stronger then stock i am going to need a new clutch/flywheel etc. I want to order the parts ahead of time withought pulling the tranny off and having to find out that way. Can anyone help me out with..
How many teeth fly wheel?
Input spline on clutch? etc.
anything else i need?
its a 1970 4 speed tranny.
thanks in advance,
Jimmy

Cyclone · 11-01-2008, 11:42 AM

Been a few years, but ours was 168 tooth, 11" disc, 10 spline input. Pull it down to check for sure, you can re-use (resurface) your flywheel if not cracked or teeth messed up. We got all our parts at NAPA parts, no waiting, all in stock.

DB Smith · 11-01-2008, 02:24 PM

Quote:

Originally Posted by Cyclone

168 tooth, 11" disc, 10 spline input.

+1.......Same set up on my small block with a Saginaw. I used a 12" clutch (biggest I could find to fit a 168t flywheel), but 11" is good too.

I got a great deal on a clutch kit from these guys....http://fortwayneclutch.com/product_3.html

**WorkinLonghorn** · 11-01-2008, 04:43 PM

I thought these trucks with v-8s came with 12" clutches (mine did). If yours has a "considerably stronger then stock " engine,I would think about going to a 12". If nothing else,it would last longer.

DB Smith · 11-01-2008, 07:32 PM

Quote:

Originally Posted by WorkinLonghorn

I thought these trucks with v-8s came with 12" clutches (mine did).

Maybe. My '69 had an 11" behind a 283 when I got it, but that may not have been stock.

My 6 bangers both had 10" clutches and the same (168t) size flywheel.

It's heavy, but like the 12" with my fresh 355. The pressure plate is the three finger (coil spring) type.

**WorkinLonghorn** · 11-01-2008, 11:14 PM

Quote:

My '69 had an 11" behind a 283 when I got it, but that may not have been stock.

That (283) wasn't an option for 1969.
I did some checking and for 1969 C-10;
Standard clutch was 10" with the 250ci.
11" with the 307ci
Optional was 11" with the 292
12" with the 350 or 396 (higher holding pressure on 396)
For C20 you could get the 11" with the 250 ci and 3 spd or np 435 4 SPD.

koolky · 11-01-2008, 11:18 PM

Quote:

Originally Posted by WorkinLonghorn

I thought these trucks with v-8s came with 12" clutches (mine did). If yours has a "considerably stronger then stock " engine,I would think about going to a 12". If nothing else,it would last longer.

Was your truck a CST? If you boguht a truck with a standard trans and CST the clutch was broght up to 12" on the v8.

koolky · 11-01-2008, 11:22 PM

I take that back, brain fart. 350 and up came with 12". 250 came with 10" and 292 came with 11".

powerline84 · 11-02-2008, 07:15 AM

If you use a 12 inch clutch you need a 12 inch fly wheel right?
by the way are our truck borg and beck or diaphram style on the pressure plate?
is there any real benefit of going with an aluminum fly wheel?
thanks for all the help by the way

Blackbird66 · 11-02-2008, 07:47 AM

12in clutch needs a 12 pressure plate. Flywheel will not change, unless you use a late model one piece rear main seal block. You DO NOT WANT or NEED an aluminum flywheel. The lack of rotational mass will hurt drivability, and result in a loss of torque.

powerline84 · 11-02-2008, 08:58 AM

cool thanx. Do you know is it the borg and beck style or diaphram

**truckdude239** · 11-02-2008, 09:15 AM

mine has an 168 tooth 11 inch cluck 10 splines. i used a good ac delco cluicth and had the flywheel turned

Blackbird66 · 11-02-2008, 10:21 AM

in a truck that is over 35 in age, you don't know what you have until you take it a part and see......... since you can get a quality clutch from napa, this should not cause you any excess down time. I'm running the same clutch with my 330hp gmpp 350 ho, as with the stock 307. The only slippage I have is excessive wheel spin

**WorkinLonghorn** · 11-02-2008, 10:23 AM

My manual shows that the 10 + 11" were diaphram.

Lugnut64052 · 11-02-2008, 01:12 PM

You should be able to run either a Borg & Beck or a diaphragm . . . whichever your preference is. Guys, correct me if I'm wrong, but I always understood B & B setups to be heavier duty. They don't engage quite a smoothly though. Diaphragms engage cushier but don't have quite the raw clamping power of a B & B.

Some flywheels are double drilled and will take either an 11" or a 12" clutch. Blackbird66 is right-- you don't want an aluminum flywheel. They're a racing piece designed to reduce rotational mass and aid quicker revving. A heavier flywheel = a smoother running engine.

DB Smith · 11-02-2008, 02:20 PM

Quote:

Originally Posted by Lugnut64052

You should be able to run either a Borg & Beck or a diaphragm . . . whichever your preference is. Guys, correct me if I'm wrong, but I always understood B & B setups to be heavier duty. They don't engage quite a smoothly though. Diaphragms engage cushier but don't have quite the raw clamping power of a B & B.

Some flywheels are double drilled and will take either an 11" or a 12" clutch. Blackbird66 is right-- you don't want an aluminum flywheel. They're a racing piece designed to reduce rotational mass and aid quicker revving. A heavier flywheel = a smoother running engine.

On the nose, Lugnut !!
The pressure plates use the same bolt pattern.

Powerline,
Here's a good deal on a 12" (coil spring) kit if you are thinking about running a B&B type.
It's from that same outfit: Fort Wayne Clutch & Driveline.
http://cgi.ebay.com/ebaymotors/Chevy...mZ190263337513
Might save you some $$$$$. A comparable kit might run ya $200.

powerline84 · 11-02-2008, 05:03 PM

db smith do you think that clutch will handle 375 ftlbs of torque? if so thats a damn good price

DB Smith · 11-02-2008, 05:22 PM

I'd say so. It's pretty heavy and really grabs.

I'm running one behind a 9:1 355 with an RV cam, World Products 2.02 heads, and Edelbrock intake. I'm not sure how many horses it puts out, but it seems to me the clutch could handle more than it makes.

You could give them a call and ask 'em what they think. These guys are easy to work with. (800) 258-8243

powerline84 · 11-02-2008, 05:46 PM

awsome thanks for all the info and quick responses ..you guys kick ass

DB Smith · 11-02-2008, 06:05 PM

No sweat! Glad it helped !

powerline84 · 11-03-2008, 03:09 PM

i emailed Fort Wayne Clutch & Driveline and they said that clutch kit they have on ebay would work just fine for my application. I will probably get it. I will probably get a new fly wheel from them to because the ones on summit claim only a racin clutch will fit or some bullcrap so ill just get one from them that i know will fit. I dont know of anywhere in my dads town that will turn a flywheel and as far as i know its origional so i would rather go new since everything else will be.

DB Smith · 11-04-2008, 04:20 AM

Yeah, By the time you pay a machine shop to resurface a flywheel you've spent enough that you may as well buy a new one.

11-01-2008, 11:28 AM	#1
powerline84 Greasemonkey Join Date: Jul 2008 Location: Clarksville, TN Posts: 232	clutch questions Since i am putting a new crate motor in thats considerably stronger then stock i am going to need a new clutch/flywheel etc. I want to order the parts ahead of time withought pulling the tranny off and having to find out that way. Can anyone help me out with.. How many teeth fly wheel? Input spline on clutch? etc. anything else i need? its a 1970 4 speed tranny. thanks in advance, Jimmy __________________ 1970 cst-10 longbed speed My Baby http://67-72chevytrucks.com/vboard/s...=1#post3113923 Last edited by powerline84; 11-01-2008 at 11:30 AM.

11-01-2008, 11:42 AM	#2
Cyclone Registered User Join Date: Oct 2004 Location: Sonoma, CA Posts: 318	Re: clutch questions Been a few years, but ours was 168 tooth, 11" disc, 10 spline input. Pull it down to check for sure, you can re-use (resurface) your flywheel if not cracked or teeth messed up. We got all our parts at NAPA parts, no waiting, all in stock.

11-01-2008, 04:43 PM	#4
WorkinLonghorn Senior Member Join Date: Dec 2006 Location: Studio City, Calif. Posts: 2,856	Re: clutch questions I thought these trucks with v-8s came with 12" clutches (mine did). If yours has a "considerably stronger then stock " engine,I would think about going to a 12". If nothing else,it would last longer. __________________ '69 GMC C2500 Custom Camper, 8 1/2' bed, New GM 350, NP 435 Close Ratio 4spd. Trans., 3.73 Dana-60 open.Camper and Trailer wiring, PS, PB, AC, tach , three gas tanks, 2nd owner, Work-Truck supreme. Best $300 I ever spent.

11-01-2008, 11:22 PM	#8
koolky 67-72 Addicted Join Date: Oct 2007 Location: Guelph Ontario Posts: 256	Re: clutch questions I take that back, brain fart. 350 and up came with 12". 250 came with 10" and 292 came with 11".

11-02-2008, 07:15 AM	#9
powerline84 Greasemonkey Join Date: Jul 2008 Location: Clarksville, TN Posts: 232	Re: clutch questions If you use a 12 inch clutch you need a 12 inch fly wheel right? by the way are our truck borg and beck or diaphram style on the pressure plate? is there any real benefit of going with an aluminum fly wheel? thanks for all the help by the way __________________ 1970 cst-10 longbed speed My Baby http://67-72chevytrucks.com/vboard/s...=1#post3113923 Last edited by powerline84; 11-02-2008 at 07:20 AM.

11-02-2008, 07:47 AM	#10
Blackbird66 Registered User Join Date: Feb 2008 Location: Shelbyville, KY Posts: 51	Re: clutch questions 12in clutch needs a 12 pressure plate. Flywheel will not change, unless you use a late model one piece rear main seal block. You DO NOT WANT or NEED an aluminum flywheel. The lack of rotational mass will hurt drivability, and result in a loss of torque.

11-02-2008, 08:58 AM	#11
powerline84 Greasemonkey Join Date: Jul 2008 Location: Clarksville, TN Posts: 232	Re: clutch questions cool thanx. Do you know is it the borg and beck style or diaphram __________________ 1970 cst-10 longbed speed My Baby http://67-72chevytrucks.com/vboard/s...=1#post3113923

11-02-2008, 09:15 AM	#12
truckdude239 Senior Member Join Date: Sep 2005 Location: Lewisville, Nc Posts: 10,217	Re: clutch questions mine has an 168 tooth 11 inch cluck 10 splines. i used a good ac delco cluicth and had the flywheel turned __________________ David fuller Ase Certified Mechanic Click here to help support our board!! 1971 Chevy c-10 under going a 4.8l LSx swap Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=421305 2007 Honda Accord my daily 145kmiles 2002 Honda Accord 4 door With 330k(sisters car) 2005 toyota Avalon 228k( brothers car) 2002 Sububran 5.3 245k 2000 Tahoe 5.3l 378 General manager for Marco's Carwash & lube Last edited by truckdude239; 11-02-2008 at 09:15 AM.

11-02-2008, 10:21 AM	#13
Blackbird66 Registered User Join Date: Feb 2008 Location: Shelbyville, KY Posts: 51	Re: clutch questions in a truck that is over 35 in age, you don't know what you have until you take it a part and see......... since you can get a quality clutch from napa, this should not cause you any excess down time. I'm running the same clutch with my 330hp gmpp 350 ho, as with the stock 307. The only slippage I have is excessive wheel spin

11-02-2008, 10:23 AM	#14
WorkinLonghorn Senior Member Join Date: Dec 2006 Location: Studio City, Calif. Posts: 2,856	Re: clutch questions My manual shows that the 10 + 11" were diaphram. __________________ '69 GMC C2500 Custom Camper, 8 1/2' bed, New GM 350, NP 435 Close Ratio 4spd. Trans., 3.73 Dana-60 open.Camper and Trailer wiring, PS, PB, AC, tach , three gas tanks, 2nd owner, Work-Truck supreme. Best $300 I ever spent.

11-02-2008, 01:12 PM	#15
Lugnut64052 Middle-aged Curmudgeon Join Date: Jun 2008 Location: Independence, MO Posts: 753	Re: clutch questions You should be able to run either a Borg & Beck or a diaphragm . . . whichever your preference is. Guys, correct me if I'm wrong, but I always understood B & B setups to be heavier duty. They don't engage quite a smoothly though. Diaphragms engage cushier but don't have quite the raw clamping power of a B & B. Some flywheels are double drilled and will take either an 11" or a 12" clutch. Blackbird66 is right-- you don't want an aluminum flywheel. They're a racing piece designed to reduce rotational mass and aid quicker revving. A heavier flywheel = a smoother running engine.

11-02-2008, 05:03 PM	#17
powerline84 Greasemonkey Join Date: Jul 2008 Location: Clarksville, TN Posts: 232	Re: clutch questions db smith do you think that clutch will handle 375 ftlbs of torque? if so thats a damn good price __________________ 1970 cst-10 longbed speed My Baby http://67-72chevytrucks.com/vboard/s...=1#post3113923

11-02-2008, 05:22 PM	#18
DB Smith Old Shovel Rider Join Date: Oct 2007 Location: Rain City, WA. Posts: 117	Re: clutch questions I'd say so. It's pretty heavy and really grabs. I'm running one behind a 9:1 355 with an RV cam, World Products 2.02 heads, and Edelbrock intake. I'm not sure how many horses it puts out, but it seems to me the clutch could handle more than it makes. You could give them a call and ask 'em what they think. These guys are easy to work with. (800) 258-8243 __________________ Daryl.... *'68 C/10 Stepside* *2007 Build Page* *DS Originals* *Old Bikers.US* Last edited by DB Smith; 11-02-2008 at 05:25 PM.

11-02-2008, 05:46 PM	#19
powerline84 Greasemonkey Join Date: Jul 2008 Location: Clarksville, TN Posts: 232	Re: clutch questions awsome thanks for all the info and quick responses ..you guys kick ass __________________ 1970 cst-10 longbed speed My Baby http://67-72chevytrucks.com/vboard/s...=1#post3113923

11-02-2008, 06:05 PM	#20
DB Smith Old Shovel Rider Join Date: Oct 2007 Location: Rain City, WA. Posts: 117	Re: clutch questions No sweat! Glad it helped ! __________________ Daryl.... *'68 C/10 Stepside* *2007 Build Page* *DS Originals* *Old Bikers.US*



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11-03-2008, 03:09 PM	#21
powerline84 Greasemonkey Join Date: Jul 2008 Location: Clarksville, TN Posts: 232	Re: clutch questions i emailed Fort Wayne Clutch & Driveline and they said that clutch kit they have on ebay would work just fine for my application. I will probably get it. I will probably get a new fly wheel from them to because the ones on summit claim only a racin clutch will fit or some bullcrap so ill just get one from them that i know will fit. I dont know of anywhere in my dads town that will turn a flywheel and as far as i know its origional so i would rather go new since everything else will be. __________________ 1970 cst-10 longbed speed My Baby http://67-72chevytrucks.com/vboard/s...=1#post3113923

11-04-2008, 04:20 AM	#22
DB Smith Old Shovel Rider Join Date: Oct 2007 Location: Rain City, WA. Posts: 117	Re: clutch questions Yeah, By the time you pay a machine shop to resurface a flywheel you've spent enough that you may as well buy a new one. __________________ Daryl.... *'68 C/10 Stepside* *2007 Build Page* *DS Originals* *Old Bikers.US*

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