Rear axle not stock

[Jsupreme]

1972 f100 4x4 4speed. Everything is stock, except the rear axle.
The tranny is the 435
The rear axle should be a h2 3.50 (3.6M)
The rear axle back there now is a Dana 60.
Eventually I want disc brakes all the way around. I don't like having 8 lugs out back and 5 in the front.
What is the stock axle that came on this truck and how hard will it be to find one? Any identifyers, or upgrade to rear axles I should keep an eye out for?
Thank you in advance!!

[71cc]

What is the (3.6m) ? The 3300# axle is a 9" axle, the 3600# is a heavier 9-3/8" axle. I don't what your codes designate.

[zainyD]

As stated, your original rear axle was a Ford 9". If you can, look for a later model 75-79 F150 4x4 or 78-79 full size Bronco and get both the front and rear axles. This will allow you to upgrade to open knuckles, ball joints, and disc brakes on the front axle and 31 spline rear axle shafts in the rear. Will be a bolt-in upgrade and well worth your time.

[Jsupreme]

As stated, your original rear axle was a Ford 9". If you can, look for a later model 75-79 F150 4x4 or 78-79 full size Bronco and get both the front and rear axles. This will allow you to upgrade to open knuckles, ball joints, and disc brakes on the front axle and 31 spline rear axle shafts in the rear. Will be a bolt-in upgrade and well worth your time.

Awesome!!
Thank you!!

[71cc]

The 73 and up 9 inch is wider flange to flange and leaf spring pad distance. You probably can't find one, but the 3600# axle was a 31 spline axle with bigger bearings. I suspect that was original equipment on your truck.

[Jsupreme]

The 73 and up 9 inch is wider flange to flange and leaf spring pad distance. You probably can't find one, but the 3600# axle was a 31 spline axle with bigger bearings. I suspect that was original equipment on your truck.

How do I identify this out in the field??