8 3/4 vs 9 3/4

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efriedrich

69 383S
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I'm worried that my new 440(500 HP Plus) is going to be to much for my 8 3/4 (489). I drive it hard but never thought much about it with my 383 since I did'nt run slicks but that will be changing. I'll get to the point. Anybody out there ever narrow a truck Dana 60 to fit an A body. How much did it cost and where you happy with it. A new moser goes for about 3000 fully loaded ready to bolt in. I have the wants but i'm not spending that kind of doe. I want to do it for around a third of that. Can it be done. I realize there are a lot of variables that need considered, so please let me here your opinions oh wise ones. I have a dana 60 from a 74 3/4 ton Dodge P/U lined up for $75.00 complete from break to break. Its a 4.10 with limited slip. Seems to good to pass up and sounds like a good place to start for my Dif. Project. Thank for the help.:dontknow:
 
I am currently contemplating the same scenario. I sold the 8 3/4 out of my Dart, and now need to put something back.

Cass (Dr. Diff) can build you a nice Dana complete (minus brakes) for $2k shipped to your door. All new axles, gears, bearings, third member, housing straightened and powder coated, cut to your width, perches welded, etc. I know it can be done cheaper locally, but not by me.

Now, where am I going to find 2 grand?!?
 
As long as you don't need a pinion snubber using a truck rear is not a problem . what you'll need to get is brakes , you can use them off your 8 3/4 unless they are the SBP stuff, axles and more than likely spiders as I don't think the sure grip in that rear is the same spline count , usually 30 , as what is available aftermarket , you may have to buy a new sure grip as that truck rear probably has a trac lock , they aren't that good , the puls is you can sell it to someone who wants to add a suregrip to their truck. You'll also need housing ends .

The Dr. Diff rear is a very good price considering what you get .
 
Two reasons to not use the truck rear are the tubes are extremely thick, about twice as thick as a passenger car rear and secondly if you don't have a case spreader they are a real pain in the *** to set up. Even if you have the spreader the side bearing preload and backlash adjustment is done with shims, still a pain in the ***.

This is what I would do if you can swing it, buy a Strange S60 housing and axle package. You can order it in any width so you could narrow it for additional tire clearance and wheel options if you want. This housing comes with side bearing adjusters for easy setup. Buy the truck rear and use the trac loc and gears out of it. You can get the housing with leaf spring perches already welded on and the Mopar ends. You can use the brakes off your 8.75.

Some of those truck rears had 30 spline axles so be sure to check that before you order anything. If it has 30 spline axles you can use the axles out of the 8.75 if you don't narrow the rear.

The S60 housing with ends and leaf spring mounts will set you back about $670 plus shipping. It also has the snubber mounts on it that the truck rear lacks.
 
All good points and ideas Guitar Jones, I was wondering why the truck axels were heavier. Where is the best place to get axels, springs & snubber from. Does any one have a good link for DR. Diff. What width would I want if I'm using the 11x2.5 drums w/ stock spring location.

I here what your sayin Brian T. My cuda cost what, 3000 and change new and I have spent how much on it in the last 26 years (LOL), and I'm only 42. How much more money in my lifetime will I throw at this glorious addiction called "Mopar".
 
efriedrich said:
All good points and ideas Guitar Jones, I was wondering why the truck axels were heavier. Where is the best place to get axels, springs & snubber from. Does any one have a good link for DR. Diff. What width would I want if I'm using the 11x2.5 drums w/ stock spring location.

I here what your sayin Brian T. My cuda cost what, 3000 and change new and I have spent how much on it in the last 26 years (LOL), and I'm only 42. How much more money in my lifetime will I throw at this glorious addiction called "Mopar".
Click to expand...

Speaking from experience, always more than what you've got!!!
 
Hey efriedrich, When I was drag racing, with 600 HP + the 8 3/4 (489) with 456 gears and slicks,never gave me a problem. If you just want to spend the money and add weight to your car,go ahead; dana 60`s are cool to look at under any car. In fact I have a few under cars, but just because the factory put them in place. My experience has been that a dana 60 is not necessary; but if that is what you want, I know that nothing else will suffice and these other guys should be able to help you. God bless, Wayne
 
RM23U/Wayne, Actually I dont want to do it at all, but I have several friends that have broken several 8.75's (ring failures I think) between them. On the other hand I have come across guys like yourself who are putting some real horse power through their 8.75 with no problems. I guess I will just run the 8.75 and If I break it I worry about it then.
 
BrianT, keep pushin brother, one day you will mash the loud pedal and it will all be worth it, I think (LOL).
 
Don't sell the 8 3/4 short plenty of guys running in the 9's with them..check out Moser or strange for your components from what i've seen quality much better then others...
 
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