So, for my Viper V10 swap, I was going with a Dana 60 from Moser, until all of a sudden the price skyrocketed over $1500 due to unforseen reasons..

So, I found a beautiful rebuilt 489 third member with a sure-grip, and 3.71 gears, I picked up a 72 B-body housing (It's going into a 72 B-body,) and have ordered the Wilwood brake kit, and green bearings suggested for it..

Now, I've also ordered a 8 3/4 back brace from Moser, for $84, is there anything else I should do? Will the factory axles be fine?

We're looking at around 600 horsepower, torque would be around the same (Those V10's, it's certainly no shortage) any input would be appreciated.

 

I would up grade it to 35 spline axles... Plain fact it will be easier to get the Dana60 built for it and cost about the same. either that or put a 9" Ford in it..

 

35's will require a spool, Detroit Tru Trac makes a 33 spline differential.

When I did my son's back brace I used a chain ratcheting come along from each end and over the yoke to put tension on it while I welded. I was shortening it after with an arbor jig. Before welding and after cutting the ends off I was surprised how far from center each tube was, this can be considered normal after 40yrs of use. After welding under tension it came back the other way but closer to center.

If you search rear axles you'll find many opinions, mine is weld a brace under tension and use an arbor jig when doing ends.

 

The Dana 60 was $4600, as of right now, I have $1183 invested in the 8.75, and I have every piece except the Wilwood brake kit, and that's another $600.

 

Don't I know it, cost was the reason we put an 8.75" in my son's Mustang, had most of the stuff.

My rule of thumb is up to 500hp for the 8.75". Use what you got and the brake kit should bolt right on a Dana if that day ever comes.

Have you braced, shortened or welded rear housings before?

 

I don't know how you can build a Mopar 8 3/4 cheaper than a Ferd 9". In fact in the Spokane area, there's probably as much as twenty times as much Ford 9" stuff show up for sale as anything Mopar.

For a Viper? I don't think an 8 3/4 would even be on the table if it were me. Either Ford 9 or Dana. Find someone else to build it.

 

This project all along has been a major cost heavy situation.. Which I realized getting into it..
I have this theory, that if I spent four grand on a rear end, realistically the car would never get finished..
If I can change it at a later date if it does break? I don't have an issue, But a friend of mine, with a 9.5 second 64 Valiant with a 440.. Somewhere around 750-800 horsepower has no problem with his 8.75 Mopar, with the same parts I'm running..

And he's using slicks!

 

Kevman89

Your "B" body will be 1000 - 1200 lbs heavier than the Valiant, and you (I presume)are putting the manual six speed transmission in your build?


8 3/4's are not known for their longevity behind a stick or a trans brake.

If you don't thrash it you'll be ok. Thrash it and you'll be spending again!

 

I like to drive my cars and to get out and be seen is my goal. you can replace it later if need be

 

I don't plan on beating on it, I'm more concerned about the frame twisting than the rear end breaking to be honest.. There's some things you just can't replace...