Need some rear diff help

[hemihead]

I have two 6 bolt rear diffs.. the funny thing is the axle tube on each diff measure differently and I am wondering if some one shortened 6 bolt axles to fit in a 5 bolt diff.

The axel tube (measured from the center section to the inside of the square mouning flange) on one measures about 20" +/- 1/8" and the other axle measures about 21" or so.

Does any one know what a axle tube on a 5 bolt would be?

I want to switch to 5 bolt axles but was going to purchase the axles and drums from CPP. If I indeed have a 5 bolt diff, I'll go to the wreckers and purchase some used axles.

[Longhorn Man]

it sounds like the short one is a mid to late 1970 rear. Gm widened it in mid '70 in preperation for the wider 5 lug rear.

[hemihead]

The rear is set up for tariling arms suspension. Did they have this past 1972.

[Green Machine]

The wide rear is the one you want to keep if swaping in newer 5 bolt axles from a junkyard. Aftermarket 5 lug axles are available for the shorter rear, but since you have your pick, use the wider one and get the used axles, much cheaper.

[Longhorn Man]

72 was the last year for coil springs and trailing arms.

[hemihead]

So do you guys think that for the shorter rear end I'll find 5-bolt axles

[JimKshortstep4x4]

5 bolt axles are used in the longer rear end and will be too long for the shorter differential.

Jim

[hemihead]

Are you guys saying the longer 6 bolt axles are the same length as the 71/72 5 bolt axles and therefore interchangeable?

[Longhorn Man]

exactly