'71 C10 Diff swap

[C10aussie]

Hi - Call for help from Australia!

My '71 Stepside has a 12 bolt disc brake rear end and I want to swap it back to a standard 10 bolt drum setup.

I have found a diff in the US I can import here, but it's from a '67, which apparently is 1in shorter than the '71 at each end?

I was going to fit it and use spacers on the rear wheels. The rear end has 10in 5 slots and 275 BFGs.

Does anyone have experience on this one please?

What other parts will I need to restore the rear end to original, the upper/central control arm etc, and I cant seem to find the part number for it on the Classic Industies website.

Any help is appreciated.

Thanks a lot