Sure grip Swap

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SB69GTS

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Can you guys confirm if I am right, I can get any 8 3/4 rear end whether it be a 742 or a 489 and make it a suregrip with any suregrip pumpkin and put whatever gears I want later on. The only thing I have to watch for my a-body, is that the rear end comes from a a-body or the perches will have to be moved. Also, are the clutch type better then the cone, and does the 489 only come with the cone. I believe the 742 had both. Thanks all
 

Can you guys confirm if I am right, I can get any 8 3/4 rear end whether it be a 742 or a 489 and make it a suregrip with any suregrip pumpkin and put whatever gears I want later on. The only thing I have to watch for my a-body, is that the rear end comes from a a-body or the perches will have to be moved. Also, are the clutch type better then the cone, and does the 489 only come with the cone. I believe the 742 had both. Thanks all

Yes I prefer the clutch (disc) type mostly because it's easier to rebuild and a non-abody rear end housing will have to have the tubes and axles shortened to fit an abody. Some of your questions I'm really not sure of, like I don't believe the 489 ever came with anything other than the cone type but with these rear ends you just never know. Talk to this guy, he does know. http://www.doctordiff.com/

Terry
 
Yes, you can interchange a complete 741,742,489 center section (AKA "pig" "chunk" or whatever) the ring and pinion must match the case (489, 741, or 742). You can swap around the carriers though. The two Sure Grip types can be interchanged between the carriers if the matching differential axle bearings are retained. The outside diameter of the cups are the same between the 741/742 and the 489, the inner cone differs. I prefer the clutch type, it is a Dana Powerlock and you can play around with the clutch pack and make it super tight or loosen it up depending on your preference. FWIW, the Dana 44 30-spline powerlock clutches and other internal parts are the same as in a 8 3/4 Mopar. For more, follow the link below....

http://www.moparfins.com/Repairs/8-3-4_Rebuilding/Information_on_Mopar_Rears.htm
 
Found a 742 axle and housing that I want to use, it does not have the sure grip, if I read this post correctly, I cn use any 742 suregrip assembly/pumpkin from any a,b,c bodied car and not the 489 ...right?
 
Found a 742 axle and housing that I want to use, it does not have the sure grip, if I read this post correctly, I cn use any 742 suregrip assembly/pumpkin from any a,b,c bodied car and not the 489 ...right?
Right!All the 742 centers will fit any 8 3/4 housing,be it A,B,C,E,
 
Found a 742 axle and housing that I want to use, it does not have the sure grip, if I read this post correctly, I cn use any 742 suregrip assembly/pumpkin from any a,b,c bodied car and not the 489 ...right?

You can use the 489 and 741 also in any a,b or c 8 3/4" housing as long as you use the proper axles (length and spline design) designed for the three different pumpkins. What you can't do is mix parts, eg. crown and pinion, bearings between the 741,742 and 489 pumpkins. If the the pumpkin/housing has let's say the 742 as the last three digits in the pumpkin casting number then only parts for a 742 (gears and bearings) must be used, you can't mix and match.
 
Found a 742 axle and housing that I want to use, it does not have the sure grip, if I read this post correctly, I cn use any 742 suregrip assembly/pumpkin from any a,b,c bodied car and not the 489 ...right?

Lets try to make this easier: ANY complete pumpkin will bolt in ANY 8 3/4 rear.

Either posi unit can be installed in ANY of the three case numbers (741, 742,489).

ONLY the PINION gear cannot be interchanged between cases. You have to have the correct ring and pinion gears for the correct number case.
Hope that helps.

Greg Purcell
 
Lets try to make this easier: ANY complete pumpkin will bolt in ANY 8 3/4 rear.

Either posi unit can be installed in ANY of the three case numbers (741, 742,489).

ONLY the PINION gear cannot be interchanged between cases. You have to have the correct ring and pinion gears for the correct number case.
Hope that helps.

Greg Purcell

Decided against the 742 without suregrip because the guy wanted too much for a non suregrip. Picked up a sandblasted, primed, housing with axles and new brakes and leaf springs and shock plates atttached with a 741 suregrip from a 70 dart. So now I have the rear end that will line up with my 69 Dart. What I want to do is remove the 741 and put in a 742 or 489 suregrip pumpkin with 3.55 or 3.91 gears. Correct me now ---> remove drums, remove the 5 or so nuts, slide out axles, unbolt the 741 slide in the 742/489 pumpkin and the put the axles back etc. The axle's, bearings etc. should all line up ....correct, or is there something else that I will have to do.

Thanks all for the help so far
 
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