Axle Shaft Interchange

[PaddyR]

I've measured my 1970 rear end between backing plates and have 57". I pulled a shaft and it measures 31 5/16". So I think I'm safe that it has the later 71-72 rear end. Up to what year axle shafts will fit in this to give me 5 lug? Brake shoes are 2" wide if it makes a difference.
Thanks

[leftybass209]

65-69 axles are 30 3/4 inches. 70 axles are 31 1/2 inches.

[67c10rustbuket]

Moser says 1970-1981 chevy truck, 31 5/16"

http://http://www.moserengineering.com/axles/gm-axles/chevy-custom-alloy-axles/1970-1981-chevy-c-10-truck/1970-81-gm-truck-2wd-spline-30.html

[PaddyR]

I'm measuring from outside of flange to the end of the axle and I'm getting the 31 and 5/16"
Have read on the forum that the 57" backing plate to backing plate is the later 71-72, Lefty am I right here?
If I am can I use a later year c10 axle say up to 81 ?
Thanks

[PaddyR]

Thanks Dan you just answered my question so up to 81 axles will work in the wide 1970 for a swap to 5 lug

[67c10rustbuket]

Originally Posted by PaddyR

Thanks Dan you just answered my question so up to 81 axles will work in the wide 1970 for a swap to 5 lug

Yes, I used 72 axles in a 70 housing but any 12 bolt truck axles up to 81 if you're junkyarding.

[Steve-W]

I'm actually considering the same swap and someone told me you have to also count the amount of splines on the axle (not counted mine yet,,guessing its 30?)

[PaddyR]

Yes my 31 5/16" are 30 spline.

[Steve-W]

Hey Paddy a question for you, if you are changing the shafts..will you also change all bearing and stuff, or leave it as is?

[PaddyR]

Steve, I'm changing the bearings and seals when I swap out the shafts. My truck has been sitting since 90. I'd change the seals for sure when you change the shafts

[Steve-W]

I'll follow your lead ��