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View Full Version : Is a Mopar 8 3/4" worth setting up???

Ric
03-18-2006, 08:22 AM
I used to be a big Mopar nut, and I remember the 742 and 489 casting of the 8 3/4" axle having ridiculously huge pinion shafts... 1.75" for the 743, and 1.875" tapered to 1.75" on the 489. They're set up like the 9" Ford, using a removable 3rd member and whatnot. They don't have near the hypoid offset as the 9" though, which should make them more efficient. However, they don't have the 3rd bearing, either. Any strength that would be lost to that is made up with the behemoth pinion shaft sizes(which I might add are larger than a Dana 60 pinion). Is there any reason why this axle wouldn't be a good candidate for swapping into an F-body?

Some dude on LS1Tech mentioned the torque arm mount, but it could be set up just like the 9"... welded to the housing.
keliente
03-18-2006, 09:40 PM
IMO it is not worth the frustration when you can find 12 bolts, 9 inches, and Dana 60's ready to bolt under the car for around $2k.
Ric
03-19-2006, 08:19 PM
As for me, I agree. I'm liking the sound of the D60 setup a LOT... more efficient than the 9", handles tons more power, weighs only a few lbs more.

I just wondered, because I hear a lot of whining and crying about each one of these. The 12-bolt breaks, the 9" is too heavy/power-consuming, and the D60 is just a boat anchor, blah-bla-b-bl-blaahhh....
02z28ls1
04-05-2006, 05:04 PM
Anybody have any weight figures on a Dana 60,Ford 9, or a 12 bolt-just for comparison sake. I seem to remember the 60 being really heavy.
keliente
04-06-2006, 01:35 PM
The moser 12 bolt weighs 188 lbs.

Ric, you need to try and make a decision based on what you need. As long as there are people in this world, someone will be pissing and moaning about one product or another. I've seen people swear against 12 bolts in an M6, but then I know a guy personally running consistent 10's with his. It is all a lot of hearsay really. I think the best thing to do is call up a few sponsors and see what they recommend for you.

I went with the 12 bolt just because it bolts in without any driveshaft shortening/etc. I put it in by myself in half the afternoon.