Rearend questions - trying to put a 9 inch in a mustang

The axle to axle distance on a 65-66 is 56.25" This is also the same dimension as the 57-59 Ford 9" rear. Spring perches arew also the same. The Lincoln Versailles 9" is one inch wider. And again the perches are correct for a Stang. The 67-70 rears are 58.25". The Fairlanes, 57-59 Ford, 65-70 Stangs,Maverick/Comet, Granada/ Monarchs all share the same spring spacing.

ther lincoln and the 80 granada rear axle would be the best fit for a 64/66 mustang. the granada is the easiest swap and can use the stock mustang 8 inch axles and brakes. pinion angle will be off but is fixed with shims. overall width for the 64-66 is 58 inches wheel to wheel.

SadbutTrue said:

And can i use any 9 inch case with any 9 inch third member with any 9 inch axles? What can interchange between all 9 inch rearends and what can't?

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Some axles are 28 spline and some are 31 spline, so no, you can't.
Also, there are big bearing housing ends and small bearing housing ends.
Narrowing a housing runs about $150 and requires a fixture to make sure the ends are perpendicular to the axle centerline and that each end lines up to the other end AND passes thru the centerline of the carrier. You'd be suprised on some housings to cut the housing ends off the housing, and install the fixture and slip the ends back on without narroing them any, and see how much the housing was out of alignment. The fixture consists of a thick walled tube that is trued to be perfectly straight, a bare center section with aluminum bushings where the axles would normally enter the carrier for the tube to pass thru, and set of bushings that the center will slip over the tube, but the outside is made for the axle bearing recess in the housing end. Usually there are a couple of these, one for big bearing and one for small bearings.

You're existing 8" axles will fit in the right 9" housing and you can even use the drum brakes off your 8", but I'm not sure which housing it is and it's probably hard to find one that is the correct length. If you can find a passenger car with a 9" with the right housing ends, you could have it narrowed and use your axles and brakes. Now if you want it narrower, you need to check your spline engagement on your existing axles, or whatever axles and housing you intend to use. When you pull an axle out, you can see that the splines are longer than where they fit into the carrier. I've seen budget narrowed rears that needed an 1" narrower on each side, the housing was narrowed and an 1" of axle was cut off each end and the end beveled with a grinder to mimick the stock look (makes for easier engagement) and the ends of the splines where cut were cleaned up with a small triangular file. If you have a higher horsepower application (above 400 horse) you'll likely want 31 spline axles and I think those were only in trucks (way too wide) and large land barge type cars (Lincolns and old station wagons.

Another thing to consider, and I didn't read your wheel/tire post, but if you're considering late model wheels, by using a bit wider rear end, you'd eliminate the need for the spacers and longer studs on the rear.

You can also be lucky like me and have someone give you a chromed (and rust) '57 station wagon 9" with 3.50 gears and a Trac Loc.

Wow, excellent timing on these posts. I just bought a big bearing 9" out of a ?? 73 ?? F-150. I want to narrow it slightly to run some fatter tires. My question is to install it I want to scrap leaf springs and use a 4 link. Has anyone here ever done this?? The project car is a 73 mach, What do I attach the subframe to?? I know that I will attach to the rear of the floor pan area, and also somewhere over the axle (well planned as you can tell), Should I extend it to the rear of the car?? Will there be much support from the rear of the car?? What should I use for the subframe, a box tubing or round tubing?? This will be my first attempt at something like this. Any help will be appriated.

1320stang said:

Some axles are 28 spline and some are 31 spline, so no, you can't.

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You will not find any small bearing 9" axles that have 31s inside unless they were put there by a PO. Any vehicle that Ford deemed "needed" the 31s got the large bearing axle housing as well. You just gotta know if it came from the original ride or not. If it has the axle tag on it it is VERY unlikely to have been retrofitted for racing.

That being said...I know of at least one 9" small bearing rear end that has 31 splined axles in it. It is in my garage right now

Ford4Fun said:

Wow, excellent timing on these posts. I just bought a big bearing 9" out of a ?? 73 ?? F-150. I want to narrow it slightly to run some fatter tires. My question is to install it I want to scrap leaf springs and use a 4 link. Has anyone here ever done this?? The project car is a 73 mach, What do I attach the subframe to?? I know that I will attach to the rear of the floor pan area, and also somewhere over the axle (well planned as you can tell), Should I extend it to the rear of the car?? Will there be much support from the rear of the car?? What should I use for the subframe, a box tubing or round tubing?? This will be my first attempt at something like this. Any help will be appriated.

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Ford4fun,
Here's a picture of a 4-link rear clip assembly from the art morrisons site.

4-link clip

Its a lot of work putting the rear subframe assembly in, but it sure is a nice setup when finished. There are numerous options as far as floor, wheel tubs etc. The tubing used for subframes is normally 2x3 box. As for wall thickness, i'd say .125.

Maybe this site will help.

http://www.ridgenet.net/~biesiade/Fordrears.html

the 57/58 ford, 64-66 hipo and the versi/granada axle would be the factory direct fit into a 65/66 mustang. the versi has disc brakes so that would require some aditional parts and work. It almost worth it to have a new housing built. Last I checked, if you find a granada housing it would cost you 300 bucks and thats for a fresh junk yard piece, unless you find it yourself.

I've got a complete Versailles 9 inch for sale in the classifieds with good rotors for $350.