replacement 12 bolt rear

Dwight Southerland · 10-06-2007, 02:36 PM

Alan - I agree with you 100%. If you are wanting to build a top quality rear end, and I think it is a good investment, the aftermarket pieces are definitely the way to go. Looking at the stocker population, the majority of the cars are serviced by aftermarket housings - 12 bolt GM, 9" Ford, Chrysler 8 3/4 & Dana 60. Maybe there should be an accepted "definition" that says any GM product can use a 12-bolt, any Ford product can use a 9" and any Chrysler (and I guess AMC) can use an 8 3/4 or Dana 60. It's almost like that now; in fact, most would argue that it is. It would just simplify matters to make it a ruling and put it in writing.

NovaMan · 10-10-2007, 04:38 AM

Suppose you already have a couple stock GM 12-bolts, but you don't have piles of cash lying around. What would you do? Beef up the better of the two stockers, or sell one (or both) and get an aftermarket unit?

Dwight Southerland · 10-10-2007, 08:39 AM

Beef it up. Nothing wrong with the old stuff if done well. Just if you are starting from scratch with nothing (no housing) the new stuff is a good consideration. I know top A, B, and C stick cars running old housings and have for 20+ years.

Dave Goob Cook · 10-10-2007, 10:44 AM

Tom's Differentials sells a carrier cap kit for about $70, it upgrades the driver side cap, and comes with 1/2" cap screws for the driver side, 7/16" upgrade cap screws for the passenger side.

On a side note, when the new housings were introduced, Tom refused to sell them because in his opinion, the cases were not within usable tolerances for his standards. That was the last word I had from him on the subject 3-4 years ago.

I have 2700+ passes on my old A-Body 12-bolt with the Tom's cap kit, no troubles, and have a car out there that is 3200# + driver running 8.60's with the old M/W cap kit, he kills a Pro gear about every 300+ passes, but no housing troubles.

Robert Pare Racing · 10-10-2007, 04:42 PM

The MW unit is the best out there. All my cars have them, and the big Ford ends, etc. MW is one scenario where you get what you pay for.

Joe Martens · 10-10-2007, 09:02 PM

Ditto to what Robert said. If you do use the stock GM housing, use the billet caps. Some type of rear end brace is a good idea, also.

10-06-2007, 02:36 PM	#1
Dwight Southerland VIP Member Join Date: Dec 2001 Location: Arkansas - In the middle of everything. Posts: 2,002 Likes: 64 Liked 783 Times in 195 Posts	Re: replacement 12 bolt rear Alan - I agree with you 100%. If you are wanting to build a top quality rear end, and I think it is a good investment, the aftermarket pieces are definitely the way to go. Looking at the stocker population, the majority of the cars are serviced by aftermarket housings - 12 bolt GM, 9" Ford, Chrysler 8 3/4 & Dana 60. Maybe there should be an accepted "definition" that says any GM product can use a 12-bolt, any Ford product can use a 9" and any Chrysler (and I guess AMC) can use an 8 3/4 or Dana 60. It's almost like that now; in fact, most would argue that it is. It would just simplify matters to make it a ruling and put it in writing.

10-10-2007, 04:38 AM	#2
NovaMan Member Join Date: Sep 2004 Location: Kalamazoo, MI Posts: 117 Likes: 0 Liked 0 Times in 0 Posts	Re: replacement 12 bolt rear Suppose you already have a couple stock GM 12-bolts, but you don't have piles of cash lying around. What would you do? Beef up the better of the two stockers, or sell one (or both) and get an aftermarket unit? __________________ ~Pete 1970 Nova

10-10-2007, 08:39 AM	#3
Dwight Southerland VIP Member Join Date: Dec 2001 Location: Arkansas - In the middle of everything. Posts: 2,002 Likes: 64 Liked 783 Times in 195 Posts	Re: replacement 12 bolt rear Beef it up. Nothing wrong with the old stuff if done well. Just if you are starting from scratch with nothing (no housing) the new stuff is a good consideration. I know top A, B, and C stick cars running old housings and have for 20+ years.

10-10-2007, 10:44 AM	#4
Dave Goob Cook Member Join Date: Dec 2006 Location: Indy Posts: 422 Likes: 0 Liked 1 Time in 1 Post	Re: replacement 12 bolt rear Tom's Differentials sells a carrier cap kit for about $70, it upgrades the driver side cap, and comes with 1/2" cap screws for the driver side, 7/16" upgrade cap screws for the passenger side. On a side note, when the new housings were introduced, Tom refused to sell them because in his opinion, the cases were not within usable tolerances for his standards. That was the last word I had from him on the subject 3-4 years ago. I have 2700+ passes on my old A-Body 12-bolt with the Tom's cap kit, no troubles, and have a car out there that is 3200# + driver running 8.60's with the old M/W cap kit, he kills a Pro gear about every 300+ passes, but no housing troubles.

10-10-2007, 04:42 PM	#5
Robert Pare Racing Member Join Date: Aug 2004 Location: Mother Earth Posts: 265 Likes: 0 Liked 2 Times in 1 Post	Re: replacement 12 bolt rear The MW unit is the best out there. All my cars have them, and the big Ford ends, etc. MW is one scenario where you get what you pay for. __________________ Rapare-Racing.com

10-10-2007, 09:02 PM	#6
Joe Martens Senior Member Join Date: Dec 2001 Location: North Olmsted, Ohio Posts: 791 Likes: 638 Liked 198 Times in 71 Posts	Re: replacement 12 bolt rear Ditto to what Robert said. If you do use the stock GM housing, use the billet caps. Some type of rear end brace is a good idea, also. __________________ Joe Martens AA/Stock 3969

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