step side rear ends wider?

[1moretoy]

I'm a little confused on the width of the rear end in my truck. Everything I have read states there were two different width rear ends for our trucks. 55.5" and 57" flange to flange. Mine measures 59". My truck is a 70 1/2 ton short step. Did step sides come with wider rear ends? I have converted to a fleet and I'm going to have it rebuilt, new posi, ford style axles ect. Either way I'm going to narrow it. Just wondering why it measures different then what everyone else says.

Thanks in advanced

[Mike C]

Where are you measuring from/to? Stepsides are the same as fleetsides depending on the year. 67-69 have the narrower rear. Sometime in 70 they switched to the wider so both wide and narrow exist. 71-72 is just the wider rear.

Leaf spring or coils? Do you have a pic to see if a different housing has been swapped in?

[1moretoy]

Originally Posted by Mike C

Where are you measuring from/to? Stepsides are the same as fleetsides depending on the year. 67-69 have the narrower rear. Sometime in 70 they switched to the wider so both wide and narrow exist. 71-72 is just the wider rear.

Leaf spring or coils? Do you have a pic to see if a different housing has been swapped in?

Measuring from the back of flange to back of flange. It is a coil set up with drum brakes.

[Mike C]

I just measured the 69 housing I pulled from my truck last week. It's close to 57" and is the narrower version.

[1moretoy]

Originally Posted by Mike C

I just measured the 69 housing I pulled from my truck last week. It's close to 57" and is the narrower version.

So being mine is a 70 and 59" it must be the wider version. I wonder how many people actually measure their rear end vs just listen to what everyone says.

[michael bustamante]

alot of people do. you have a more desireable rear end as you can take the axles out of a 71-72 and just slide them into your housing for a 5 lug conversion

[1moretoy]

Originally Posted by michael bustamante

alot of people do. you have a more desireable rear end as you can take the axles out of a 71-72 and just slide them into your housing for a 5 lug conversion

Ok thanks for the info. I plan on narrowing the rear end when I weld on the torino housing ends. What is the overall width of the rear end on the earlier style? Wheel mounting surface to wheel mounting surface. Originally I planned on doing 2"off each side but if I did that I would only be what a stock width rear would be right? So maybe I should do 3"'-3-1/2"

[michael bustamante]

are you tubbing? running something wider than a 12" wide rim? im running 10" on my 67 with the stock rear and it snugs nicely. you can run 12" wide rims no problem before modding is necessary

[1moretoy]

Originally Posted by michael bustamante

are you tubbing? running something wider than a 12" wide rim? im running 10" on my 67 with the stock rear and it snugs nicely. you can run 12" wide rims no problem before modding is necessary

I'm going to tub if necessary as I have no bed floor in now. I plan on running a 12" wide rim but want a deep dish wheel. The wheels will be custom 3pc so I'm pretty flexible with the backspacing.

[Fitz]

Originally Posted by michael bustamante

are you tubbing? running something wider than a 12" wide rim? im running 10" on my 67 with the stock rear and it snugs nicely. you can run 12" wide rims no problem before modding is necessary

Be very careful with the section width of the tire if you try a 12 in rim. I run 10 in rims in the rear and there was 3/8 inches clearance between the tire and the fender lip and the same amount between tire and bedside before I tubbed it. I do not believe that there is any tire that can be installed on a 12 in rim that would not rub.

[Mike C]

I don't think the truck 12 bolt is the best housing to spend money on for narrowing, but YMMV. Why not do a 9 inch and not have to buy special housing ends, just use the OEM ones. Or for that matter, a Dana 60 would be better. My past is littered with destroyed truck 12 bolts...

[1moretoy]

Originally Posted by Mike C

I don't think the truck 12 bolt is the best housing to spend money on for narrowing, but YMMV. Why not do a 9 inch and not have to buy special housing ends, just use the OEM ones. Or for that matter, a Dana 60 would be better. My past is littered with destroyed truck 12 bolts...

I'm not spending the money just to narrow it. I'm going with a kore3 c6 zo6 rear brake kit and he designed the kit around the torino ends. I'm rebuilding the 12bolt with a true trac posi 3.73 gears and axles with pressed on bearings. I'm pretty sure it would cost more then $1600 to build a 9". Plus I already have the 12 bolt from the truck.

[Mike C]

This is all just for discussion. Your plan will work, but for the same $ I think you can do better so I'm not dissing your idea.

My own experience with the truck 12 bolt is it's not that strong if you ever want to really put the power to it. I've broken ring gears, pinion gears, even snapped the Eaton posi case in half on one. And that was just big tires and medium power. After 7 different versions of truck 12's my Jimmy now has a semi-float 14 bolt.

Ford style housing ends costs almost as much as buying a complete 9" off Craigslist. You can debate 9" versus the passenger car 12 bolt or a Dana 60, but there is no doubt that all 3 are stronger than the truck 12 bolt.

Sell your 12 bolt, Narrow the 9" housing using the stock ends, buy aftermarket axles and differential and be good to go. Same thing if you prefer a Dana 60. Full float 60's aren't very expensive and are much stronger than the 12 bolt.

I'm not sure if you can get Ford housing ends that use GM brakes, but that would be the one reason to stay with the 12 bolt. Brake parts are expensive. Speedway gets $500 almost for a drum brake setup. But the Ford setup I prefer to the c-clip eliminator kits that you add to your GM axles.

Most of my research into 9" was using the housing ends on a Dana 60 to make an offset axle for an early Jeep. The brake cost is nuts as I was trying to budget build. I've got all the tools to narrow the housing, so that's no cost. Only expense was new axles and bearings if you got a complete axle with brakes since early Jeep and big Ford are same bolt pattern. But new drum parts and stupid expensive.

[1moretoy]

Originally Posted by Fitz

Be very careful with the section width of the tire if you try a 12 in rim. I run 10 in rims in the rear and there was 3/8 inches clearance between the tire and the fender lip and the same amount between tire and bedside before I tubbed it. I do not believe that there is any tire that can be installed on a 12 in rim that would not rub.

Even after I tub it and get a wheel witht The correct backspacing you think I'll have a problem with clearance?

[Fitz]

Originally Posted by 1moretoy

Even after I tub it and get a wheel witht The correct backspacing you think I'll have a problem with clearance?

When I tubbed my stepside clearance went from 12 inches to 20-1/2. If that isn't wide enough for you sell the truck!

[michael bustamante]

i agree on the 9" rear end

[michael bustamante]

depends on your backspacing really. but ive seen some wheels tucked real good under our steppers. research research......

[1moretoy]

Originally Posted by michael bustamante

depends on your backspacing really. but ive seen some wheels tucked real good under our steppers. research research......

It's no longer a step side I converted to a fleet side.

[In The Ten Ring]

"wider rear end?"

Are you saying my stepside makes my butt look big?

[67 cst swb]

I agree with going the 9" direction. You can get 9" stuff very reasonable if you look around. Much stronger rearend, much easier to change ratios, much much easier to narrow, just a much better option.
You could probably sell that late 70 6 lug for a few $ to get you started.