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Discussion Starter #1
;)

Year & Model Axle Length Notes
1965-1966 Mustang 57.25 inches
1967-1970 Mustang 59.25 inches
1971-1973 Mustang 61.25 inches
1977-1981 Versailles 58.50 inches
1967-1973 Mustang, Torino, Ranchero, Fairlane 59.25 inches to
61.25 inches
1957-1959 Ranchero and station wagon 57.25 inches
1966-1977 Bronco 58 inches
1977-1981 Granada/Versailles 58 inches
1967-1971 Comet, Cougar, Mustang, Fairlane 59.25 inches
1971-1973 Mustang 61.25 inches
1964 Falcon 58 inches
1967 Cougar 60 inches
1967 Fairlane 63.50 inches coil springs
1972 Ford Van 3/4 ton 68 inches
1973-1986 Ford Van 3/4 ton 65.25 inches
1957-1959 Ranchero and station wagon
57.25 inches
narrowest 9" housing
1966-1977 Bronco 58 inches 5-on-5 1/2 inch diameter bolt circle
1967-1973 Torinos, Rancheros, Fairlanes 59.25 inches or
61.25 inches
1967-1971 Comets, Cougars, Fairlanes 59.25 inches
1975 Mustang II 8" 57.00 inches
1974 Maverick 8" 56.50 inches
 

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Where do you measure from for these readings. Inside backing plate flanges or to the very ends of the backing plate flanges???

Scott
 

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Discussion Starter #3
I believe these measurements are from end to end. I had this list stashed in my tool chest and thought it might be useful to the members.

I think I was looking for a Lincoln Versailles (9" w/discs) rearend for one of my other Cougars and I was not sure what the difference was in width.
 

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great tech Rick!

Hey, did you ever get a chance to post the pics of your x10 wheels on a rear view? I didnt see them in the gallery.
 

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Discussion Starter #5
Crazy,

Posted that pic of the 15x10's from the rear that you wanted to see. Let me know if that is the view you wanted!

RickJ
 

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Thanks Rick.
A bit off topic, but what is the backspacing on the wheels.
Is there some good info on the net for figuring backspacing/offset, etc..?

Or maybe you can tell me what is correct for a 15x10 to fit my 67 without poking the tire out of the wheel well like a lowrider.

I am thinking of the 15x10 Weld Pro Star or the Edelbrock 454 style. I also need to find something that will fit rear discs too...

Click here for a pic of the Edelbrock 454
 

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Discussion Starter #7
I checked that link in your post. That is a fantastic looking wheel. As for my backspacing, I bought those wheels in the early 90's and I can't remember off the top of my head what the backspace was.

I will roll it into the driveway tomorrow and measure them. Like I said, 1/2" more on backspace would pull them in just enough to keep them from rubbing with people in the back. Or I recommend 9 1/2" in width.

Rick J
 

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I just sent you a PM. LOL

I rolled the lip of the wheel well with a baseball bat, so they don't rub anymore. They did when I first put them on though.

RickJ
 

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While looking for info on the rear axle shaft I have to take out I found the following, it says the measurements are from flange to flange.These measurements are from flange to flange. Subtract 5" for bare housing length.

65-66 Mustang 57.25 inches
67-70 Mustang 59.25 inches
71-73 Mustang 61.25 inches
77-81 Versailles 58.50 inches
74 Maverick 8" 56.50 inches
75 Mustang II 8" 57.00 inches
67-73 Mustang, Torino, Ranchero, Fairlane 9" 59.25 inches to 61.25 inches
57-59 Ranchero and station wagon rears, 57.25 inches
66-77 Bronco 9", 58 inches
77-81 Granada/Versailles, 58 inches
67-71 Comet, Cougar, Mustang, Fairlane, 59.25 inches
71-73 Mustang, 61.25 inches
64 Falcon 58 inches
67 Cougar 60 inches
67 Fairlane 63.50 inches (coil springs)
72 Ford Van 3/4 ton 68 inches
73-86 65.25 inches
57-59 Ranchero and station wagon 57.25 iches (narrowest 9" housing)
66-77 Bronco 58 inches but has 5-on-5 1/2 inch diameter bolt circle
67-73 Torinos, Rancheros, Fairlanes 59.25 inches or 61.25 inches
67-71 Comets, Cougars, Fairlanes 59.25 inches

Where to find the 9" rear axle
67-73 medium and big block Mustangs and Cougars
66-71 Fairlanes, Torinos, Montegos, Comets, and other Ford intermediates
with big blocks
57-59 V8 Fords and Mercurys
77-81 Lincoln Versailles & Trucks

Type of 9" axle housings
67-73 Mustang/Cougar - light duty, thinnest housing material, small axle
bearings, 28 and 31 splines
57-68 passenger car and 1/2 ton truck - medium duty, stronger than Mustang
type, 28 and 31 splines
Ranchero/Torino - heavy duty thick wall housing, 3.25 inch diameter axle
tubes with flat tops
69-77 Galaxies (coils), Lincolns (coils), and late pickups (leaf)- 3.25
inch diameter all the way to the backing plate, coil housings have upper
control arm mount

How to recognize 9" housing centers
57 - no dimples, flat center band up the center of the rear cover, bottom
drain plug
58-59 - two dimples on back of housing, flat center band, some had drain holes
60-67 - two dimples, flat center band, oil level hole in back cover
63-77 Lincoln, LTD, Thunderbirds had 9.375 inch centers, housings were cut
away at the gasket surface for ring gear clearance, one curved rib at the front
top portion of differential. Strong, but no gears.

Types of 9" Axles
28 spline axles cannot be shortened and resplined (they're tapered)
Some can: 69-73 Mustang and Cougars have a straight 28 spline axle.
72 and earlier 31 spline axles have the ability to be shortened
73 and later 9" (big cars) have a 5-on-5 bolt circle and the axles cannot be
shortened
67-73 Mustang axles identified by wheel flange:
oval hole - 28 splines two large holes and counter sunk center - 31 splines




--------------------------------------------------------------------------------
Credit for this page to:
Ford Rear Dimensions
by Dave_C and the Fordnatics mailing list.

http://www.mustangsandmore.com/ubb/FordRearDimensions.html
 
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More questions than answers

This morning in an effort to solve someone elses problem I discovered my own. I went to take pics of what the axles look like for 28 and 31 splines and somehow I ended up looking at my tag for whatever reason. Again for whatever reason I decided I would decode my tag. Bored I guess. So I opened my manuals to specifications page and looked up WFD-A and mucho to my surprise I found the Ford Shop Manuals call out 3.50 locking diff. Well thats all fine cept for the data plate clearly shows 3L25 as does my door data plate and my Marti report indicate. Sooooo, I went to every source of data I could find today and everywhere I goes it says I have a 3.5 traclok notta 3.25
I also found this link interesting for those interested in making tracloks for near free
http://www.woodyg.com/fairlane/finfo/TractionTechTip5.html
 

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That list shows the 67-71 Cougar as being 59.25, I have a 9" from a 69 Cougar that's 60" even from flange to flange. If you add brake drums it will be 60.25.
Mark
 

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Today I tried to put a 1969 fastback mustang differential and axels in my 68 Cougar. The axels from the 69 mustang were and inch short on both sides any ideas why? Accoring to the data in this post both should have been 59.25 - interchangable.
 

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8 to 9 inch

I hope someone can help me with this. I have 2 cougars, one a 1971 and the other a 1968. I would like to put the 71 nine inch in the 68 and according to the list of rear ends the 67 to 71 are the same (59.25) with the exception of in 1967 there was also a 60 inch. I measured both that I have and the 8-inch in the 68 measures 54 inches from housing flange to housing flange. Add the 5 inches that is stated and this should come out to 59.25. The 71 on the other hand, has a measurement of 55.5 housing flange to housing flange. I thought they were supposed to be the same but they are not. Is it possible that the axle flange sticks out more on the 8 inch to make up the deference and does it really mater about the 1.5-inch deference? Thanks

Dennis

 

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The information is in error

First of all Cougar and Mustang rear axle widths from 1967 - 70 are the same, approximately 60 1/4" from drum face to drum face.

1971 - 73 are 1" wider and won't work well in the earlier cars unless you are using custom backspacing wheels.

Jon,
The Mustang differential ought to work fine. How come you are trying to swap them? You do realize that the axle on one side is shorter than the other? Are you trying to install a left side axle into the right side or vise - versa? I can't recall which one is shorter without going out to the garage.
 

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The Versailles unit has discs. It is an absolute pain to use in a Cougar, you are going to be able to do it more easily and cheaper buying a set of aftermarket disc brake conversion parts.
 

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Hardtop said:
My question is, which of the 9 inch's mentioned had disc brakes ?
You could use the disc brakes of the rear of a Crown Vic or an older Explorer. They have 8.8s but the patterns are the same and should bolt onto a small bearing 9” or an 8” without a problem.
 

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65 Fairlane is the same as a 65 Mustang. 57 1/4"

The narrower rear will bolt in to a 67-70 Cougar and give an inch each side for more offset wheels. Check for tire interference to the axle bumper and leaf spring.
 
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