Bellhousing for 72
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Race Director
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Bellhousing for 72
Looking to buy a bellhousing for my sb 72, can someone tell me the correct size? I've seen 10" or 11" clutch assemblies? From 350 to muncie m 20. Also is it 26 or 27 input with 32 output splines for 72 only?
Race Director
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From: Forked River NJ
For a 72 it should be an 11 inch clutch with the bigger 621 bellhousing. The Muncie has a 26 input spline and a 32 output spline. Somewhere in the 70 model year it went from 10 to 26 input and 27 to 32 on the output. The later transmissions are a little stronger due to this change.
I have a 621 bellhousing. It had a slight crack at the bottom but I had it correctly fixed. It won't be NCRS bit it worked fine for a few years behind my motor.
I have a 621 bellhousing. It had a slight crack at the bottom but I had it correctly fixed. It won't be NCRS bit it worked fine for a few years behind my motor.
Last edited by Gordonm; Mar 9, 2007 at 09:56 AM.
Melting Slicks
Joined: Dec 2005
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You can find used ones on ebay, it doesn't have to be the exact "621" bell (last 3 digits of GM's p/n), just one that will accommodate an 11" clutch. Maybe someone who knows part numbers will chime in an give you some others that will work.
http://cgi.ebay.com/ebaymotors/GM-be...98718875QQrdZ1
http://cgi.ebay.com/ebaymotors/1969-...88871060QQrdZ1
http://cgi.ebay.com/ebaymotors/CHEVR...98496676QQrdZ1
You can also buy an improved thicker replica of the "621" from Keisler Engineering for about $240.
http://www.keislerauto.com/gm/transm...ellhousing.asp
Don't buy one that has been re-welded if you can avoid it.
Last edited by shafrs3; Mar 9, 2007 at 10:32 AM.
Thread Starter
Race Director
Joined: Jun 2005
Posts: 10,189
Likes: 206
2018 Corvette of Year Finalist
2017 C3 of Year
For a 72 it should be an 11 inch clutch with the bigger 621 bellhousing. The Muncie has a 26 input spline and a 32 output spline. Somewhere in the 70 model year it went from 10 to 26 input and 27 to 32 on the output. The later transmissions are a little stronger due to this change.
I have a 621 bellhousing. It had a slight crack at the bottom but I had it correctly fixed. It won't be NCRS bit it worked fine for a few years behind my motor.
I have a 621 bellhousing. It had a slight crack at the bottom but I had it correctly fixed. It won't be NCRS bit it worked fine for a few years behind my motor.
Thanks for the heads up on the new part, I'm going to try my luck used first, but your next in line if I can't find a good one!
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Thread Starter
Race Director
Joined: Jun 2005
Posts: 10,189
Likes: 206
2018 Corvette of Year Finalist
2017 C3 of Year
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