66-67 Cadillac Rearends

Questions about all other brand differentials.
Monzallac 425
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66-67 Cadillac Rearends

Postby Monzallac 425 » Sun Nov 29, 2009 12:51 pm

Jim, Doug here from Hbody. org (HWM) , a guy on a Cadillac board wants to swap his 3.21 non posi chunk for a 2.94 Posi chunk .

Both are 66 rears . Only two ratios available from the info I found ( 2.94 non A/C - 3.21 A/C )

I found out that they made a commercial rear and a regular rear .

Is this a straight ( chunk for chunk) swap ? ( as long as they are regular rears )

Will the gears on the non posi work on the posi carrier? ( or are the carriers different?)

Let me know asap , Thanks , Doug

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monzaz
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Re: 66-67 Cadillac Rearends

Postby monzaz » Sun Nov 29, 2009 8:57 pm

Doug, MAN i WISH i WAS MORE Knowledgeable on the Caddy rears. from the 60's.

we just do not get any call for rebuilding them.

Here is what I would say.

If the rear has a drop out pig you can swap them housing to housing

If the rear is integral cover on the rear one piece housing all parts exit from the rear cover. The gear will bolt up to each other carrier as posi and non posi does not make a difference in the gears.

What does make a difference in the carriers non posi and posi are the series that they MIGHT BE.

The 2.94 might be a 2 series carrier where as the 3.21 could be a 3 series carrier ...THIS MEANS you will need a spacer plate of some sort if you want to use the 2.94 on the 3.21 posi

NOW if he wants to just take the 2.94 posi chunk and put it in the other housing it will fit just fine as long as the rears are the same size diff. If he wants to take the 3.21 gears and put them on the 2.94 posi carrier you might need a spacer plate. REMEMBER IT MAY be the same series...measure like this (reference picture)

if your carriers (2.94 and 3.21 ) next to each other LOOK like the picture you will need a spacer (meaning they are stepped ) if the match even then you are good to go bolt it on and install the 321 and posi unit. Jim
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carrier breaks 1.jpg
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Monzallac 425
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Joined: Sun Nov 29, 2009 1:12 am

Re: 66-67 Cadillac Rearends

Postby Monzallac 425 » Mon Nov 30, 2009 10:14 pm

Thanks Jim for the help. Doug


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