NJ WTB: Aluminum bellhousing - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**ScottH** · 02-03-2013, 01:51 PM

Looking for an aluminum bell housing for an 11" clutch.
If anyone can help me out pls LMK condition and price shipped to 08753.

Thanks
Scott

RPBurris · 02-04-2013, 03:52 PM

how do you know if it will take an 11" clutch? I attached some pics of a bellhousing i have laying around (for like 15 years now). LMK if it might work. I can get the numbers off the side of it but when i looked them up before they didnt seem to pull anything up.

DesertCat · 02-04-2013, 06:32 PM

Looks like a 10.4" type. If you post the numbers I can probably tell you for sure.... I just went through all this myself.

Scott, also need to know if you are looking for a 5-1/8" or 4-5/8" hole. The larger one for truck transmissions, smaller for M20-22, T10, super T10, etc....

**ScottH** · 02-04-2013, 07:21 PM

Thanks guys, yes # on the bellhousing would help out a lot.

Good point Desertcat, need the smaller diameter hole (4 5/8").

RPBurris · 02-05-2013, 03:10 PM

It looks like the numbers are 3840387 ?? I found this pic on my phone and did not get a chance to look at it last night. Any info on it would be more than i have now.

**ScottH** · 02-05-2013, 03:25 PM

I'm guessing the last number is a 3.....if so I found this:

casting #3840383 is a GM part Number 3858403 (group 0.683) - so it's often refered to as a "403" Bellhousing (just 'Housing' to GM).
It is for the 10 1/2" clutch set-up. This was the standard housing for many standard and performance vehicles with the 'small' clutch for many years.
This clutch size is most commonly found with the smaller diameter ring gear with 153 teeth.

The 11" clutch requires a GM Number 3899621 (same group) housing.

Guess I need a 621 bell housing.

Thanks
Scott

**jocko** · 02-05-2013, 03:34 PM

yep, that's what you need - 621. Understand you probably want an original gm and it will cost less than a new one - but this company makes new repros and they are high quality. if cost not a HUGE factor, might consider one of these. Has some minor improvements over a 621 i believe - I saw these in person and met the owner at the LA Roadster show last year, looked like a very high quality part: http://www.americanrebelmfg.com/bellhousings/ The confirmed minimal runout is a nice-to-have...

02-03-2013, 01:51 PM	#1
ScottH Senior Member Join Date: Sep 2002 Location: Hampstead, NC Posts: 8,187	WTB: Aluminum bellhousing Looking for an aluminum bell housing for an 11" clutch. If anyone can help me out pls LMK condition and price shipped to 08753. Thanks Scott __________________ 1963 C10 swb fleetside 1966 GMC G1000 Handi-bus (future project) 1955 Chevy 2 dr. wagon

02-04-2013, 03:52 PM	#2
RPBurris Registered User Join Date: Mar 2010 Location: Dyer, Indiana Posts: 395	Re: WTB: Aluminum bellhousing how do you know if it will take an 11" clutch? I attached some pics of a bellhousing i have laying around (for like 15 years now). LMK if it might work. I can get the numbers off the side of it but when i looked them up before they didnt seem to pull anything up. Attached Images __________________ 1969 Chevy K20 Longbed

02-04-2013, 07:21 PM	#4
ScottH Senior Member Join Date: Sep 2002 Location: Hampstead, NC Posts: 8,187	Re: WTB: Aluminum bellhousing Thanks guys, yes # on the bellhousing would help out a lot. Good point Desertcat, need the smaller diameter hole (4 5/8"). __________________ 1963 C10 swb fleetside 1966 GMC G1000 Handi-bus (future project) 1955 Chevy 2 dr. wagon

02-05-2013, 03:10 PM	#5
RPBurris Registered User Join Date: Mar 2010 Location: Dyer, Indiana Posts: 395	Re: WTB: Aluminum bellhousing It looks like the numbers are 3840387 ?? I found this pic on my phone and did not get a chance to look at it last night. Any info on it would be more than i have now. Attached Images __________________ 1969 Chevy K20 Longbed

02-05-2013, 03:25 PM	#6
ScottH Senior Member Join Date: Sep 2002 Location: Hampstead, NC Posts: 8,187	Re: WTB: Aluminum bellhousing I'm guessing the last number is a 3.....if so I found this: casting #3840383 is a GM part Number 3858403 (group 0.683) - so it's often refered to as a "403" Bellhousing (just 'Housing' to GM). It is for the 10 1/2" clutch set-up. This was the standard housing for many standard and performance vehicles with the 'small' clutch for many years. This clutch size is most commonly found with the smaller diameter ring gear with 153 teeth. The 11" clutch requires a GM Number 3899621 (same group) housing. Guess I need a 621 bell housing. Thanks Scott __________________ 1963 C10 swb fleetside 1966 GMC G1000 Handi-bus (future project) 1955 Chevy 2 dr. wagon

02-04-2013, 06:32 PM	#3
DesertCat Registered User Join Date: Mar 2011 Location: Valley of the Sunstroke, Arizona Posts: 1,210	Re: WTB: Aluminum bellhousing Looks like a 10.4" type. If you post the numbers I can probably tell you for sure.... I just went through all this myself. Scott, also need to know if you are looking for a 5-1/8" or 4-5/8" hole. The larger one for truck transmissions, smaller for M20-22, T10, super T10, etc.... __________________ My build thread - Devastation and Reform http://67-72chevytrucks.com/vboard/s...d.php?t=567131

02-05-2013, 03:34 PM	#7
jocko Senior Member Join Date: Oct 2009 Location: Godley, TX Posts: 17,937	Re: WTB: Aluminum bellhousing yep, that's what you need - 621. Understand you probably want an original gm and it will cost less than a new one - but this company makes new repros and they are high quality. if cost not a HUGE factor, might consider one of these. Has some minor improvements over a 621 i believe - I saw these in person and met the owner at the LA Roadster show last year, looked like a very high quality part: http://www.americanrebelmfg.com/bellhousings/ The confirmed minimal runout is a nice-to-have...



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