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742 versus 489?

The clutch sure grip will fit any carrier. It is the better sure grip. Last used in 741, 742 1968.
Doug
 
As Dipstick mentioned, the larger diameter at the pinion head is to prevent pinion deflection and broken teeth, not to increase shear strength.
 
HI ,i have read this 7everal times and the question i have is can you use a 1 3/4 in pinion in a 741 ,i have a 2070741 with stock factory 1 3/8 pinion and want to up grade to the 1 3/4, whats the difference between the two the 741 and 742 any help would be greatly appreciated thank you.
 
the 742 case uses much larger pinion bearings than the 741 case -- so unless you want to machine your 741 pinion bearing pockets out to 742 bearing sizes ,,, but why bother ,, finding a 742 case is not hard -- although there is nothing wrong with the 741 case
742 case pinion bearings HM803149 / HM803110 --i.d. 1.750" ,,, o.d. 3.500"
HM89443 / HM89410 -- i.d.1.312" ,,, o.d. 3.00"
741 case pinion bearings HM89446 / HM89410 -- i.d. 1.375" ,,, o.d. 3.00"
M88048 / M88010 -- i.d. 1.312" ,,, o.d. 2.687"
 
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You want the ultimate 8 3/4? Use a 489 case, crush sleeve eliminator kit, and your golden. If ya can’t get a 489 case/crush sleeve eliminator, then stick with a 742. Wanna go big? Dana 60.....boom, drop the mic!
 
the 742 case uses much larger pinion bearings than the 741 case -- so unless you want to machine your 741 pinion bearing pockets out to 742 bearing sizes ,,, but why bother ,, finding a 742 case is not hard -- although there is nothing wrong with the 741 case
742 case pinion bearings HM803149 / HM803110 --i.d. 1.750" ,,, o.d. 3.500"
HM89443 / HM89410 -- i.d.1.312" ,,, o.d. 3.00"
741 case pinion bearings HM89446 / HM89410 -- i.d. 1.375" ,,, o.d. 3.00"
M88048 / M88010 -- i.d. 1.312" ,,, o.d. 2.687"
 
I get it now, i was confusious, on the bearing diameter,i am on the right path now ,thank you for your help and time,peace.
 
The Mopar factory used a solid sleeve but the aftermarket makes a crush sleeve. If you have the '742 professionally rebuilt, insist on the solid sleeve. I specified the solid sleeve and as I reviewed the build before they shipped it back, I asked which sleeve was used, they said crush so I had them tear down to meet my build requirements. Unfortunately, one cannot inspect the crush shield, so I hope I got what I asked and paid for.

The '742 was the performance differential until the '489 came along, so use it in good health.

For safety, get a US Car Tool driveshaft loop:
http://store.uscartool.com/Bolt-In-Driveshaft-Loop-64-72-Mopar-B-Body-70-74-Mopar-E-Body_p_21.html
 
The Mopar factory used a solid sleeve but the aftermarket makes a crush sleeve. If you have the '742 professionally rebuilt, insist on the solid sleeve. I specified the solid sleeve and as I reviewed the build before they shipped it back, I asked which sleeve was used, they said crush so I had them tear down to meet my build requirements. Unfortunately, one cannot inspect the crush shield, so I hope I got what I asked and paid for.

The '742 was the performance differential until the '489 came along, so use it in good health.

For safety, get a US Car Tool driveshaft loop:
http://store.uscartool.com/Bolt-In-Driveshaft-Loop-64-72-Mopar-B-Body-70-74-Mopar-E-Body_p_21.html
The 742 never used a crush sleeve, that was new in 69 with the 489 case.
 
The 742 uses shims, Dana 60 also. 489 is crush sleeve and a solid spacer with shims is an aftermarket upgrade the makes the 489 really strong.
 
I ran 630 HP in my 3675 pound Charger thru a 741 case with 3.91 gears going 1.6 sec 60 foot on 10 inch slicks. No trans break. Never had a problem. When a 4.3 gear spool went in, used a 489 case. The 8.75 pumpkin is stout.
 
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