Shorten 9 Inch

[Raven Rider]

I would like to get a set of AR Torque Thrusts or Crager S/S wheels.  I understand by reading a bunch of posts here that if I shorten the rear end then the choices become easier on what will fit.  Is 3/4 inch on each side the size I need, I will be paying a shop to do this so I only want to do it once?  Would it be better to go with a different dimension?  What I'm after is a new set of wheels and no hassle changing tires, I don't mind jacking up the car by the frame to get the rear end to drop to deal with changing tires and I don't want the widest rim tire combo just some thing that is wide enough and looks good.  What do you think about the number of spines on the axle because I will be doing a Posi unit at the same time?  As a side note this car isn't a big HP car just a cruse around 302 5 speed maybe an AOD in the future road car.

[RICH MUISE]

Jerry...yes, 3/4" is what I've been told here on numerous occasions. Don't think I've ever heard any different.
If you're considering brake changes in the back, now would be the time. I'd check into it, but I think being a wagon, you've already got the big drums/bearing setup back there, so that wouldn't need to change.

[Raven Rider]

Thanks Rich it will be a while before this happens I'm just getting the ducks in a row. 

[gasman826]

If you're going to cut a 9", get a better, more common housing.  '57 housing is not the strongest but they look nice under first gen Mustangs...and others.  Use a later housing that is beefier and cheaper.  I often use pickup/van housings.  Pickup axles (31 spline) can be shortened.  Some disc brake conversions require a little extra length axle...like a 1/4" per side.  If disc brakes might be in the future, consider talking with Strange or Mosier...and there are many other sources.

[hiball3985]

Sorry, just a curiosity question but you mentioned using a truck housing. I'm only familiar with the early truck 9" housings that weren't offset like passenger cars, they had equal length axles on both sides. Is there a certain year truck that started using an offset? 

[gasman826]

Truck housings are so wide there is the option to cut-to-fit.  There is enough material for a center pinion or offset pinion.  For really low cars, the drive shaft/pinion angle has the option of side offset to obtain a non zero pinion angle.

[hiball3985]

Thanks got it now.. I almost thought about using a truck rear I had but decided the expense wasn't justified for my type of driving, the Ranchero rear already had the bigger bearings and brakes. So I only used the third member and put new gears and bearings etc.

[Raven Rider]

Thanks I will talk to Strange or Mosier.  I think the housing I have that has been under my RW for 58 years is going to strong enough for my driving and it is so cheap it is free.  I do thank you for your suggestions re: the disk brake mod.

[gasman826]

I usually get $300-500 for a '57 rear end.  I usually pay $0-100 for a PU rear end.  Selling the '57 rear might offset some of the cost to narrowing a rear end.  The '57 axles are 28 spline and not practical to shorten.  A PU rear is normally 31 spline and axles can usually be shortened and redrilled for 5x4.5 wheel pattern a little cheaper than new. 

[Raven Rider]

Gasman good info I'll check into it I like to save a few bucks.