Will center section from pre 65 8 3/4 work in 65 and newer

I have heard both, yes and no. Now I need a definitive answer. Will the third member from a 64 8 3/4 with bolt on axles work with the 67 housing with the non bolt on axles?

If not, what stops them from working correctly?

Thanks in advance.

With stock axle bearings a Sure grip will fit, an open differential will not fit.

Why?

Because the centering block is 1.5" wide on a sure grip and 1965 and newer open rear.
The centering block on a 1964 and older open rear is 1.25" wide.

I can get pictures of each on an assembled 3rd member and you will see how different they are.

Ran a 64 center section in a 69 housing with no problems, non-SG setup

If you use green bearings it will work because they don't need a thrust block.

Here are pictures, see the difference in the thrust blocks? So now you can easily spot it.