Rear end width

[aggie91]

I searched on here and did not find what I was looking for.

I would like to know the width of the factory rear end, WMS to WMS for a 64-66 1/2 ton.

What other years are also that width? Lug pattern does not matter to me at this point...

Any one else know what other rear ends might be similar in width?

[SCOTI]

Originally Posted by aggie91

I searched on here and did not find what I was looking for.

I would like to know the width of the factory rear end, WMS to WMS for a 64-66 1/2 ton.

What other years are also that width? Lug pattern does not matter to me at this point...

Any one else know what other rear ends might be similar in width?

I measured the rear housing for my 68 not too long ago while investigating swap candidates. It should be the same as the 64-66 housing which is the narrower housing vs. 71-87's. It was 62" (WMS to WMS).

[Captainfab]

The '63 to early '70 rear differentials measure 62" WMS to WMS. The last one I measured was actually 62 1/8", so there is a little varience.

[aggie91]

Thank guys, I knew that someone would have the info that I need.

If I look for a 63-70 rear end for a bolt in, any would work correct? I plan on doing the pan hard mount on the PS trailing arm so the housing mount does not really matter...

[Captainfab]

For the most part yes. The '63 12 bolts had pressed on backing plates, so depending on just what you're doing that may or may not be an issue. The '63 & '64 12 bolts had the panhard bar mount on the passenger side axle tube, but as you say that doesn't matter to you. I just thought I'd mention it for the benefit of others reading this. Be careful when looking at a '70 12 bolt as this was the transition year for the widths. As I understand it, the early '70 model year differentials were the narrower and the later in the model year they were 1.5" wider, as the '71-'87 rear differentials.

[aggie91]

Thanks, Captain. I am going to look at other rear ends also. My current 9" is 56" wide and I don't feel like running super wide tires this time and I don't think that 3" spacers on each side is a good idea either...

[crakarjax]

Out of curiosity, is there a benefit to the wider or narrower track width?

[aggie91]

Originally Posted by crakarjax

Out of curiosity, is there a benefit to the wider or narrower track width?

I have changed direction with this truck and looking to go back to the stock rear end width and use a narrower tire on a 8" rim as opposed to a wider tire on a 12" rim...To me a wider track would be more stable.

[SCOTI]

Originally Posted by aggie91

I have changed direction with this truck and looking to go back to the stock rear end width and use a narrower tire on a 8" rim as opposed to a wider tire on a 12" rim...To me a wider track would be more stable.

It comes down to back spacing preference as the change in width between the years (6x-70 vs. 71-87) is minimal (1.5" total). If you like more wheel lip, the narrower width is preferable.

[michael bustamante]

Originally Posted by crakarjax

Out of curiosity, is there a benefit to the wider or narrower track width?

when switching to disc brakes it pops the front tires out more than the rear end does so people like to swap to the 71-72 rear end for that purpose, also to convert to 5 lug. I have a 70 rear end on my trailer with leafs and it is the wider rear end with 6 lug axles

[aggie91]

Originally Posted by SCOTI

It comes down to back spacing preference as the change in width between the years (6x-70 vs. 71-87) is minimal (1.5" total). If you like more wheel lip, the narrower width is preferable.

I agree, but I may end up with something other than stock to get the stance/look I am after with the wheels that I have. I might even have to order "new" custom steel wheels...I like a wider wheel lip on the rear too.