which rear end?

[yarko]

First off. I'm a total noob. I just night a 67 f100 and I plan on putting the crown Vic front end in it. I want to swap out the rear end for a newer disk brake set up. What's the common year/vehicle everyone is using? I want the bolt pattern the same as the crown Vic and I don't want to have crazy offsets. Thanks guys!

[yarko]

Just bought*

[cep62]

Welcome

the 80-83 ? F100 (not F150) had a 9 inch with a car pattern, you can easily adapt disc brakes to it .
It should be about 4 inches wider so you'll need to relocate the spring perches.

You can also use an 8.8 out of an Explorer some came with disc brakes. and they are narrower.

Where do you live?

[yarko]

I live in pine grove Ontario Canada. I'd like to do whichever rear end is the easiest....as bad as that sounds. Lol.

[yarko]

Isn't there a later f150 that had the perches in the same location?

[HIO Silver]

Isn't there a later f150 that had the perches in the same location?

None that I know of......

[Ozblitz]

Does anyone know the width of 80-83 f100 rear end, compared to width of Explorer 8.8?

[ultraranger]

There were only four model years the truck 9-inch rear ends came with a 5 x 4.5" lug pattern and they were in the 1980-1983 Bullnose Ford F100s. '94-'04 Cobra Mustang rear disc brakes and calipers can be adapted to the old style large axle bearing housing end flanges with the small lug axle pattern '80-'83 F100 9-inch rear ends. These rear ends will be about 65" from wheel flange-to-wheel flange. --very close to the width of the CV front suspension.

However, not all '80-'83 F100s had the 5 x 4.5" lug pattern. Some had the larger 5 x 5.5" lug pattern so, note the lug spacing if you find an '80-'83 F100 truck as a potential 9-inch rear end donor. All 1980-1986 Ford truck 9-inch rears came with 31-spline axles.

There are three large bearing backing plate flange patterns on the 9-inch truck rear ends. Two are the old style large bearing housing ends. One had 1/2" backing plate bolts. The other had 3/8" backing plate bolts. (The vertical distance between the center of the upper backing plate bolt to the center of the lower backing plate bolt will be 2-3/8").

The 3rd backing plate flange pattern on the ends of the axle housing tubes had the newer ''Torino' style flanges. This started around 1977 in the Ford truck 9-inch rears but is more common in the Bullnose trucks. The 'Torino' style flanges have 3/8" backing plate bolts and are directly compatible with '95-'01 Explorer rear disc brake assemblies. (The vertical distance between the upper and lower backing plate bolts will be 2.00"). However, it will require a change to a smaller wheel flange axle with a 5 x 4.5" lug pattern for the wheel flange to fit inside the hat of the Explorer rear rotors.

[Ozblitz]

Thanks Ultra, Any idea of the Explorer width? Im just trying to figure out which rear end to use? I know the orig. 68' 9" rear is a lot narrower and and the axles could be re-tapped to 4.5" pattern, but dont quite get why everyone changes to a wider axle? If you get rims w/ a deep dish wouldnt that make the track w/ the front CV be a little more inline? I would think some people would like the big beefy dragster look out back. I must be missing something?

[ultraranger]

Thanks Ultra, Any idea of the Explorer width? Im just trying to figure out which rear end to use? I know the orig. '68 9" rear is a lot narrower and and the axles could be re-tapped to 4.5" pattern, but don't quite get why everyone changes to a wider axle? If you get rims w/ a deep dish wouldn't that make the track w/ the front CV be a little more inline? I would think some people would like the big beefy dragster look out back. I must be missing something?

Wheel flange-to-wheel flange on the Explorer rear end is approximately 59".

Re-drilling/indexing the 5 x 5.5" axle flanges to a 5 x 4.5" lug pattern won't leave much material between the old wheel stud holes and the new ones. The large access hole in the axle flange throws off the ability to index the studs to be evenly spaced in between the existing wheel stud holes.

The biggest attraction of installing a wider rear end is to get rid of the bull dog look --you know, broad looking across the front and narrow across the rear. It puts the rear wheels at the same track width as the front. Widening the rear end also helps increase the stability of the truck. The wider housing width is also good if you want to run the same width wheel/tire all the way around.

The staggered look of narrower front tires and wider rear tires is popular but, your tires won't last as long because you can't rotate them.

Running the wider Dentside 9-inch rear end also has a greater probability of getting a rear end with 31-spline axles. If the 3rd member in the Dentside donor 9-inch rear end doesn't have a Traction-Lok differential, it makes it easier to install one, if you found a Dentside 3rd member with a 31-spline Traction-Lok a later date. 31-spline TL differentials are more common than 28-spline TL differentials.

Not all '80-'86 Bullnose 9-inch rear ends came with Traction-Lok differentials but they ALL came with 31-spline axles.

[Ozblitz]

I hope your not getting tired of my questions?
So, won't the dentside rear also have the flange interference you were mentioning from original bumpside rearend? Thus, preventing me from re-tapping axles to 4.5"
If I understand correctly, it seems I would run into same issue? Unless the big access hole in dentside has a different design, which will allow me to re-tap to 4.5" without a problem.

If I'm able to use a dent side rear and re-tap it, it will be better option for me, because then I can re-tap the axles when Im ready. If I use to 80-83 rear, Im forced to get different wheels.

Thanks for your help!

[ultraranger]

I hope your not getting tired of my questions?
So, won't the dentside rear also have the flange interference you were mentioning from original bumpside rearend? Thus, preventing me from re-tapping axles to 4.5"
If I understand correctly, it seems I would run into same issue? Unless the big access hole in dentside has a different design, which will allow me to re-tap to 4.5" without a problem.

If I'm able to use a dent side rear and re-tap it, it will be better option for me, because then I can re-tap the axles when Im ready. If I use to 80-83 rear, Im forced to get different wheels.

Thanks for your help!

Dentside 9-inch rear ends have the same 5 x 5.5" lug pattern as the (narrower) Bumpside 9-inch rear ends.

SOME '80-'83 F100s had 9-inch rear ends that came with a 5 x 4.5" lug pattern. --SOME had 9-inch rears with a 5 x 5.5" lug pattern.

The Crown Vic front suspension has a 5 x 4.5" lug pattern. If you found an '80-'83 F100 9-inch rear end with the 5 x 4.5" lug pattern, it would be the correct width to match the width of the CV front suspension and it would have the very same 5 x 4.5" lug pattern to match the wheel pattern on the CV front rotors.

[radioactivelarry]

First off. I'm a total noob. I just night a 67 f100 and I plan on putting the crown Vic front end in it. I want to swap out the rear end for a newer disk brake set up. What's the common year/vehicle everyone is using? I want the bolt pattern the same as the crown Vic and I don't want to have crazy offsets. Thanks guys!

Try an axle swap. Find a 60's or 70's big Ford like a Wagon, T-bird, Lincoln or big Merc because they have the 4.5 pattern and they will most likely have the big bearings and the larger backing plate bolts. You may have to also use the backing plates and drums and the brakes. There are plenty of axles around. You just pull yours and measure the length. There were plenty of combinations. If you find some that are slightly too long just have them cut to length, however you may just find the correct length. Count your splines to see if you have 28 or 31 spline, conventional or posi. This way you still have your original 9" pumpkin. This would be a good time to swap pumpkins for a gear ratio change like to 3:25 or even 3:00. The big cars will have that same ratio and will swap without any modifications.
Unless you are going to drive super fast and need to stop on a dime you won't need disc brakes. There are however conversions available for disc brake conversions.

[ultraranger]

Beware the big Ford passenger car 9-inch rears by around 1974-up had 5 x 5" lug patterns.

Unless the 9-inch axles are from a Ford factory performance car, expect 28-spline axles. I'm only aware of 31-spline axles from performance Ford cars, such as early Mustangs, Torinos, etc. with a 9-inch or '68-'72 F100s with a 9-3/8" rear end that have axles that can (safely) be cut and resplined. --same continuous diameter along the entire length of the axle shaft, no steps in the diameter.

If the axle has a step/taper just below the splines, the axle cannot be safely cut and resplined. The axles are not through hardened. Removing the case hardening of the axle to respline it will expose the softer metal. The splines will not last after this.

This is an example of a Ford axle that did not meet the above criteria but, it was cut and resplined, which removed the case hardning. --Notice anything wrong with the splines?



It will be VERY difficult to find an early set of factory axles that meets the lug pattern and length requirements and that can safely be cut and resplined. If you're going to change axles, it's much simpler to just spend the money on buying a new custom pair of axles.

[radioactivelarry]

Beware the big Ford passenger car 9-inch rears by around 1974-up had 5 x 5" lug patterns.

The big T-Birds of the up to 79 vintage had 4.5 patterns with 9" rears. Lincolns shared the same rear ends as the Granada and so forth with a 4.5 pattern with 9" rears and some had rear disc brakes which is a popular conversion for vintage mustangs. Never seen a 5.5 on a Ford passenger car of that vintage. T-birds, Rancheros, LTD's etc all had 4.5's.

Remember in the mid to late 70's cars were downsized for fuel economy because gas prices went way up! Rims from my 77 Bird would fit on my 64 Bird, and my LTD wagon!

There are LOTS of combinations out there without cutting or modifying your axles, all with 4.5 patterns. Just look around or find a lug pattern chart from a custom wheel mfg as they have listings for most vehicles.

You don't have to cut or re-spline axles if you find the right ones, 28 spline for conventional and 31 for posi. Typicality the rear ends had different length axles on right and left sides so there are plenty to chose from. Lots of Ford parts are interchangeable, that's how the factory saved money.

Example, the backup lights on 64 to 66 T-birds are the same as the cargo lamps on lots of later model Ford pickups, the ones above the rear window on the cab.

Good luck....