Weight of 7 1/4 vs 8 1/4 vs 8 3/4 vs Dana 60?

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64DartGTinAZ

64DartGTinAZ

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Anybody know of a chart with respective weights for these rear ends?

Thanks!
 
There is a diagram some where that shows how much hp they draw/use.
Weights of them I have yet to see.
 
Thanks, memike...any idea where that diagram lives? (or what keywords to use to search for it?)

I just googled trying for that and hit on a thread on the HAMB that had weights for a Dana60 and Ford and GM rear-end:

http://www.jalopyjournal.com/forum/showthread.php?t=493986

12 bolt 210lbs
S60 230 lbs
9 inch 238 lbs

Just thinking about my slant build - won't need that much strength (8 1/4 s/b fine)...how much lighter might it be? Give up the ability to quickly swap pigs to change gear ratios, but... These are all within 30 lbs of each other, so maybe it won't make that much difference regardless...

Anecdotally, from this Hemmings article, the 8 1/4 is much lighter:

http://www.hemmings.com/mus/stories/2007/01/01/hmn_feature21.html

Although not as strong as these other two units, they are reasonably easy to locate because Chrysler used them in a wide range of original applications and, secondly, this rear is much lighter than the Mopar 8 3/4-inch, without sacrificing strength.

and later in the same article:

Although lighter than the Chrysler 8 3/4-inch rear end, the 8 1/4-inch unit is heavier than some of the stock 7 1/4-inch Mopar 9-bolt assemblies it has been known to replace.

But, how much weight are we talking? 20 lbs? 100 lbs?

A guy on moparchat claims the 7 1/4 weighs 80 - 110 lbs less than an 8 3/4

http://www.moparchat.com/forums/showthread.php?t=78710

"The weak link is the spider gears and parts listed above. The only real 'beef up' you can do is add a sure grip. This will help devide the load between the spiders, axles, etc. As you know, new ones aren't available. To make the problem worse, used ones are very hard to come by. Some of the axle seals are getting scarce also. This is too bad, they are 80-110lbs lighter than an 8 3/4, too bad sure grips, spools, better axles and gears aren't available. It would be a great rear for the lower HP cars.
Bottom line, and you've already heard this, upgrade to a 8 1/4 or 8 3/4 rear, they also come with a bigger brake.
But if you really want to keep the 7 1/4, don't put more the 250HP to it and/or stock up on some spares, they're cheap."
 
I can say that the Dana 60 is a heavy *** piece of iron.....
 
inkjunkie said:
I can say that the Dana 60 is a heavy *** piece of iron.....
Click to expand...

been told by a well known superstock racer that there is 35lbs. diff. between the dana 60 and an 8 3/4; like me, he started blowing 8 3/4`s and had to go to a dana to stop it. -------------------bob
 
There are aluminum center sections for 8 3/4 rears which will lighten your rear end (or at the very least your wallet).
 
Most of the Dana 60's were out of a truck. The tubes were what made them so heavy. Truck rears had thick wall tubes. My cousin had one in his Chevy pro stocker in the 70's
 
There is this chart but it doesn't reference weight per se, just application.
 

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Recent issue of Mopar Muscle had a blurb where they said the S60, at 250 lbs, weighed about 50 lbs more than the 8 3/4 - so I guess that would put the 8 3/4 at about 200 lbs
 
I seen a Dana 60 mash a dude's hand all to pieces if that's worth anything. It was cool. To everybody but him.
 
Same parts in each, a Dana weighs about 20# more than an 8.75.

The Dana also has a better pinion position and drags less power than a 8.75.

Every car I've ever swapped didn't slow down one bit from the change to the heavier D60.
 
I just replaced my 7 /14 with an 8 1/4. The 7 1/4 is an easy two-man lift, but the 8 1/4 is much heavier. If I had to guess I'd say the 7 1/4 weighs about 120 lbs and the 8 1/4 weighs maybe 180? But I'm no weight-guesser.
 
Drum to drum w/a clutch SG & 4.10's, 8.75 I weighed @185#.
If I get a chance this wknd. I'll try to weigh the other two. I may
still go w/a SG 7.25 in my early GT, but more for novelty than any
weight savings. By the time you add a real ratio w/a thicker ring gear
and a SG unit, your probably less than 30# lighter, and a lot less
stronger.
 
i know when i swapped from a 7 1/4 to a 8 3/4 the weight difference was tremendous i could curl the 7 1/4 easily by myself 8 3/4..... not so much lol
 
Well,I may not get to weigh a 7.25 this wknd., but I did weigh the
8.25 next to my 8.75. I had a sneaking suspicion this may be the
case, but I got news for you,it is every bit as heavy as the 8.75!!
With the same flared 10" drums(30#/pair),shoes,hrdw.,park cables
brake lines,lugnuts holding the drums on,etc. it is actually a tad more
than. The axle & backing plates alone are 149#, and that's 2.94
gears w/an open diff. so..... knowing that the welded banjo housings
are lite, the 8.75 is quite svelte for it's strength. It also is why you
see the same w/the heavy reinforcements welded to them in serious
applications.
 
Weighing them can be subjective. With or without brakes, cables, etc...

The heavy duty axles are HEAVY....
 
Got a chance to pull & weigh the 7.25 last wknd. Almost
exactly 135# w/cables, lines &hose, drum to drum. 9"
brakes w/ flared drums, 2.94 open unit.
 
Killer6 said:
Well,I may not get to weigh a 7.25 this wknd., but I did weigh the
8.25 next to my 8.75. I had a sneaking suspicion this may be the
case, but I got news for you,it is every bit as heavy as the 8.75!!
With the same flared 10" drums(30#/pair),shoes,hrdw.,park cables
brake lines,lugnuts holding the drums on,etc. it is actually a tad more
than. The axle & backing plates alone are 149#, and that's 2.94
gears w/an open diff. so..... knowing that the welded banjo housings
are lite, the 8.75 is quite svelte for it's strength. It also is why you
see the same w/the heavy reinforcements welded to them in serious
applications.
Click to expand...
I see lotsa numbers but not the ones we need?lol
 
AJ/FormS said:
I see lotsa numbers but not the ones we need?lol
Click to expand...
????? If it ever stops raining this wknd., I'll re-weigh the
8.75,as I weighed that years ago w/a diff. scale just for
consistencies sake. But the OP asked for relative weights,
and I think pointing out that an 8.25 is really no lighter'n
an 8.75 , and the 7.25 is 50# lighter stock pretty much
answers that query. I may come into possession of a SG
7.25 unit, and will see what that axle comes in at if that
happens. The only D60 I have is in the tow tk., so it's up
to another member to post an actual A-bod dana stock#.:)
 
64DartGTinAZ said:
Thanks, memike...any idea where that diagram lives? (or what keywords to use to search for it?)

I just googled trying for that and hit on a thread on the HAMB that had weights for a Dana60 and Ford and GM rear-end:

HP Loss- Which Rear End Is Best

12 bolt 210lbs
S60 230 lbs
9 inch 238 lbs

Just thinking about my slant build - won't need that much strength (8 1/4 s/b fine)...how much lighter might it be? Give up the ability to quickly swap pigs to change gear ratios, but... These are all within 30 lbs of each other, so maybe it won't make that much difference regardless...

Anecdotally, from this Hemmings article, the 8 1/4 is much lighter:

http://www.hemmings.com/mus/stories/2007/01/01/hmn_feature21.html

Although not as strong as these other two units, they are reasonably easy to locate because Chrysler used them in a wide range of original applications and, secondly, this rear is much lighter than the Mopar 8 3/4-inch, without sacrificing strength.

and later in the same article:

Although lighter than the Chrysler 8 3/4-inch rear end, the 8 1/4-inch unit is heavier than some of the stock 7 1/4-inch Mopar 9-bolt assemblies it has been known to replace.

But, how much weight are we talking? 20 lbs? 100 lbs?

A guy on moparchat claims the 7 1/4 weighs 80 - 110 lbs less than an 8 3/4

7 1/4 rear end imrpovements? - Moparchat - Home of MOPAR enthusiasts worldwide!

"The weak link is the spider gears and parts listed above. The only real 'beef up' you can do is add a sure grip. This will help devide the load between the spiders, axles, etc. As you know, new ones aren't available. To make the problem worse, used ones are very hard to come by. Some of the axle seals are getting scarce also. This is too bad, they are 80-110lbs lighter than an 8 3/4, too bad sure grips, spools, better axles and gears aren't available. It would be a great rear for the lower HP cars.
Bottom line, and you've already heard this, upgrade to a 8 1/4 or 8 3/4 rear, they also come with a bigger brake.
But if you really want to keep the 7 1/4, don't put more the 250HP to it and/or stock up on some spares, they're cheap."
Click to expand...

I think you'd be fine with an 8 1/4 if you can find one for a good price. I've had one in my Jeep living behind a stroker motor with 350 ftlbs of torque and a 5 speed while turning 35" super swampers. Its seen many clutch dumps and lots of rock crawling, they are fairly stout axles under a lighter vehicle.
 
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