Original 307 Bellhousing Clutch Size 12"???? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

dan468 · 02-20-2010, 03:49 PM

I have the original bell housing to my 1972 307. Can this fit a 12" clutch assay? I'm mating it to a gen IV 454. Are all the flywheels the same size and just the clutch sizes different?

Thanks,
Dan

LONGHAIR · 02-20-2010, 04:18 PM

It depends on the 'wheel, some have both bolt-hole patterns, but I have seen them with only one. Bellhousing, I am not sure, but I would think so.

dan468 · 02-20-2010, 05:51 PM

Quote:

Originally Posted by LONGHAIR

It depends on the 'wheel, some have both bolt-hole patterns, but I have seen them with only one. Bellhousing, I am not sure, but I would think so.

I'm mostly concerned with the big block flywheel. I don't mind using a 10.4 or 11'' clutch/plate

cparman · 02-20-2010, 06:25 PM

might need some help here? The flywheels on ALL chevys are either 153 tooth, or 168 tooth. The physical OD cannot be that much different I would think. SO, if I am correct the flywheel should fit??

dan468 · 02-20-2010, 07:08 PM

Quote:

Originally Posted by cparman

might need some help here? The flywheels on ALL chevys are either 153 tooth, or 168 tooth. The physical OD cannot be that much different I would think. SO, if I am correct the flywheel should fit??

that's kinda what i was thinking too and pretty much all 454 flywheels are 168.

LMN8UR · 02-20-2010, 07:30 PM

Quote:

Originally Posted by dan468

that's kinda what i was thinking too and pretty much all 454 flywheels are 168.

My '72 was originally a 307, the bellhousing is the same one used on most / if not all manuals from 67-72 Cast #3925505. . . I currently have a 168 tooth flywheel with an 11" clutch. I was shopping for a new flywheel and clutch, and according to Summit I can put a 12" clutch under the bellhousing (As previously stated, depends on the flywheel holes.)

nplocoman · 02-20-2010, 08:58 PM

My 307 1969 with a three on the tree is an 11 inch 168 tooth. I am now running a Powerglide with a 153 tooth. All with the same housing. The holes on my original fly wheel are 12 1/2 inches. Help this helps. I don't see how a 12" will work with 12 1/2 holes in the flywheel.

monte0185 · 02-20-2010, 10:35 PM

I just put a 12" clutch on my 307 and everything bolts up great. it is the same clutch for the 454. Same splines and everything. go for it and have fun.

nplocoman · 02-20-2010, 10:39 PM

See: I know nothing!

But was your truck 3sp or a 4sp?

BOZO · 02-21-2010, 10:02 AM

If you have to change flywheels, be sure to get a 454 specific flywheel as they are externally balanced.

dan468 · 07-15-2010, 05:40 PM

I just ordered the 12'' dual friction from centerforce with 26 spline input. We'll see how it works.

- Dan

02-20-2010, 03:49 PM	#1
dan468 Registered User Join Date: Nov 2006 Location: Sun City, Arizona Posts: 430	Original 307 Bellhousing Clutch Size 12"???? I have the original bell housing to my 1972 307. Can this fit a 12" clutch assay? I'm mating it to a gen IV 454. Are all the flywheels the same size and just the clutch sizes different? Thanks, Dan __________________ 68 C-10 Build thread http://67-72chevytrucks.com/vboard/s...d.php?t=414699

02-20-2010, 06:25 PM	#4
cparman sharp as a marble Join Date: Jan 2007 Location: atlantic beach,florida Posts: 1,082	Re: Original 307 Bellhousing Clutch Size 12"???? might need some help here? The flywheels on ALL chevys are either 153 tooth, or 168 tooth. The physical OD cannot be that much different I would think. SO, if I am correct the flywheel should fit??

02-20-2010, 08:58 PM	#7
nplocoman never finish start another Join Date: Mar 2007 Location: North Platte Nebraska Posts: 432	Re: Original 307 Bellhousing Clutch Size 12"???? My 307 1969 with a three on the tree is an 11 inch 168 tooth. I am now running a Powerglide with a 153 tooth. All with the same housing. The holes on my original fly wheel are 12 1/2 inches. Help this helps. I don't see how a 12" will work with 12 1/2 holes in the flywheel. Last edited by nplocoman; 02-20-2010 at 09:03 PM.

02-20-2010, 10:35 PM	#8
monte0185 Registered User Join Date: Oct 2008 Location: Brighton, TN Posts: 1,267	Re: Original 307 Bellhousing Clutch Size 12"???? I just put a 12" clutch on my 307 and everything bolts up great. it is the same clutch for the 454. Same splines and everything. go for it and have fun. __________________ A computer once beat me at chess, but it was no match for me at kick boxing. Duct tape is like the force. It has a light side, a dark side, and it holds the world together.

02-20-2010, 10:39 PM	#9
nplocoman never finish start another Join Date: Mar 2007 Location: North Platte Nebraska Posts: 432	Re: Original 307 Bellhousing Clutch Size 12"???? See: I know nothing! But was your truck 3sp or a 4sp? Last edited by nplocoman; 02-20-2010 at 10:40 PM.

02-21-2010, 10:02 AM	#10
BOZO Old School Join Date: Jan 2010 Location: Dover,AR Posts: 185	Re: Original 307 Bellhousing Clutch Size 12"???? If you have to change flywheels, be sure to get a 454 specific flywheel as they are externally balanced.

07-15-2010, 05:40 PM	#11
dan468 Registered User Join Date: Nov 2006 Location: Sun City, Arizona Posts: 430	Re: Original 307 Bellhousing Clutch Size 12"???? I just ordered the 12'' dual friction from centerforce with 26 spline input. We'll see how it works. - Dan __________________ 68 C-10 Build thread http://67-72chevytrucks.com/vboard/s...d.php?t=414699



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