Difference between 67-70 and 71-72 axle widths

[ryan68]

I've got a coil spring 68 12 bolt axle. I know the WMS on the 71-72 axles are 1.5" wider. But, don't these axles have the 2 3/4" wide brakes instead of the 2" wide. Basically what I'm asking is if the axle tubes are the same length between the years and can I just swap out the longer 5-lug axle shafts and backs off a 71-72 onto a 67-70 axle?

Thanks for any info

[krue]

From what I understand, you will need a 3/4" spacer on each side to use the 5 lug axles (up to about 1980 or so).

[Longhorn Man]

The axle shafts are not the same width.
About a year ago, some one on here mentioned that his brake shoes were only 1/2 way into the drums...turned out some one stuffed 71/72 shafts into a 67 - 70 (early 70) rear.

[ryan68]

I already know the axleshafts are different by 3/4", but this is also the same size difference as the brake widths. 67-70 had 2" and 71-72 had 2 3/4". So if this is true, doesn't that make the tube lengths the same. Therefore, why can't I take my 67-70 housing, and put 71-72 backing plates and brakes and axle shafts and put them in my axle housing. Or do I even need to change the brake backing plates? Can I just change the shoes and drums and axleshafts?

[Longhorn Man]

I think you had optional brakes...I'd have to check my books though, I am pretty sure 2 inch was the norm on all of them.

[StingRay]

Axle tube lengths are NOT the same. The 70 up axle housings are wider than the 69 down. This is an old argument and has been proven many many times over the last 4 or 5 years. Take a tape and measure the housings for yourself. Newer axles can be retrofitted into the narrower housing using different brakes BUT the bearings will not be on the normal part of the axle intended to be the inner race. You'll be taking your chances.

[ryan68]

Thanks guys, exactly what I needed to know. I know this has been debated, just never paid attention, until I realized I need my rear axle to be wider to clear 20's.