Third member interchange?

[fr8train]

Will the 3rd's from a 64 fit a 75-79 housing?

 

[Pin_Head]

Yes, but you need to drill out the holes on the casting. If you add the fine spline spiders, the later axles will fit too. If you swap flanges the drive shaft will bolt up.

 

[fr8train]

Great! Thanks for the info. Forgive the newbie, but which casting? Or is this self evident once I am lookin at it?

 

[woody]

the holes in the third...the studs in the steel housing are to large.

the 64 will have coarse spline side gears, 68-later shafts are all fine spline, so you'll need to swap out spiders (or install a locker during the process for the later shafts)