I am looking for an 8-3/4 complete rear-end, or a housing with axels,or if I have to all seperate compenents, etc. As I look though I see ads for small bolt pattern, large bolt pattern, Housing with-out axels, third member only 492 case, 481 case, etc. I am confused!

I have a 1972 Staellite Sebring plus that I am putting a 440/727 combo in (I am removing the 318/904/7-1/4 set-up). My question is what exactly should I be looking for? Bolt pattern? width of axels, case #, sure-grip unit #, ring and pinion set up for daily driver, etc. I know A-body rear won't match up but what about C body or? Any direction would be appreciated!

Welcome! You'd want an 8&3/4 housing/axles from your body type and non A body 8&3/4's are all BBP and most are the std 10" brakes (some are 11"). check the archives for more info on what bodies use the same axle (width/perch) as yours. Want a 742 case sure grip 3rd member with somewhere from a 3.23/3.55/3.91.

The simplest way to go is probably obvious: Find an 8 3/4 axle for your model car. ALL B body axles were what is called the "large" bolt pattern. Only the A body 8 3/4 axles came in the small bolt pattern. As far as I have found, ANY 8 3/4 3rd member can physically fit into ANY 8 3/4 housing. They all use the same 10 bolt pattern. Also, in mid 1969, the '489 case 3rd member was phased in and ran until the axle went out of production at the end of the 1974 model year. The ones that had Sure Grip differentials were the Cone type. Great when new, but when they wear out, they are not easily rebuilt. A clutch type SG can be rebuilt though if you can scrounge one. They are NOT being reproduced, so you'd have to find a used one.

Thanks for the information gents. I appreciate it! Now I know what to look for. I was on the right track but just wanted to make sure. The sure-grip info is all new to me though and very helpful. So far my experience on moparts is that there are a bunch of very cool, helpful people here!

Dont play with B body axles--there are 3 or 4 different widths of axles to get lost in----when you replace an axle shaft you have to buy custom made-----if you go with an A body housing every axle shaft is 28 inches--(no dont use the small bolt pattern axles)-if you want to upgrade you can buy a yukon axle from randys for a little over a hundred dollars--i built a dana 60 A body width for a friend running a 70 roadrunner 440 stroker with a blower and a 833 4 speed----he has been racing the car for 3 years and the yukon axle splines have not migrated (twist) his car is pushing 750 hp-----and dont sweat the small brakes you can put your current brakes on the A body housing----or you can disc it up---8.75 or dana 60 i build only A or C body width because axles are always 28 inches or 30 inches---if you buy 10 sets at a time you get a handy discount and free shipping from randys too----bob

Thanks Bob!

yukon make power loks for 8-3/4


http://www.yukongear.com

Bueno!!!!

Yukon hasn't made power-locks in years.

you may be able to source a truck or van axle at a pickapart--the 2wd are more likely to be posi--ask you racer friends who is cutting down axle housings (one hour labor) source the axles and bearings---you should be able to get what you want for $500----bob

I am familiar with 3 types of 3rd members listed in order of durability: 741 < 742 < 489. Granted, pre 1970 units had the clutch-style (easily rebuildable) carrier, but all carriers will interchange between any and all cases. Gears are specific to each case. Shape of pinion is where you will find the difference in durability due to tapering and lack thereof. If you are doing a moderate 440 auto build, any case will be fine.

new yukon 8 3/4 clutch carrier at:
http://www.yukongear.com/Positractions.aspx

Rear housing selection will depend on how much tire you want to fit under there. Perches can be moved and offset sheackles can be used for clearance.

You are looking at about 63" drum to drum on your car, which is one of the widest. perch to perch, you are 47.3", which is the widest of all. The path of least resistance would be to find the original stock 8 3/4 to match your car. The fender wells are quite large to fit some meathooks under there. But, e body 8 3/4 rears are likely less difficult to find and easier on the wallet? You can move the purchases a bit, but you must watch tire/spring clearance. that is where you might consider the the reloc kit or backspace manipulation with wheels.

I wouldn't get to carried away with new axles...use stock with any 5 x 4.5 bolt pattern. your wheels will fit fine. I don't think there would be a need for an a body rear...again, the rear fender flare is huge.

brakes sizes big and small with stock drums. either will be fine for your application. I believe that the 7 1/4 backing plates should just slide right off and right onto the 8 3/4...viola.

most importantly, don't forget to add oil...and a little sure grip additive.

mike

Scored an 8-3/4 out of a 69 Charger for $225.00. Need a sure-grip unit still and the correct length axels. Stoked that I have the housing though. Going to powder coat. What's the correct finish? It isn't gloss black correct?

You know that won't bolt in don't ya???

1962-'70 measure 59.2" and 44" pad width

Once again, Yukon (clutch type) 8 3/4" power-locks have not been available for years.

B-body housing specs:

'65-'67: 54 1/4" with 44" perch on center

'68-'70: 54 15/16" with 44" perch on center

'71-'74: 57 7/8" with 47.3" perch on center

***I make a 1 1/4" offset spring hanger/shackle kit that can be used to mount a '68-'70 B-body rear into a '71-'74 B-body.