anyone know what the sierra 7" diff housing if made off? ie, can i weld it. i feel some bodging coming on!

Aluminium Joel - though it may prove difficult to weld due to it's porosity and the saturation of gear oil

damn it.

maybe have to think harder then.

anybody know off the top of their heads if sierra lobro flanges fit a capri (atlas) diff?

I know that the "preparing a sierra for motorsport" book from Ford quotes all the same special tools for setting and rebuilding the sierra diff and the Atlas.

It's just that I have seen a conversion where the axle tubes were removed from an Atlas axle, drive flanges inserted (after machining to accept oil seals, not tricky to do) and it was used as an independent diff. This was done due to the huge range of ratios avail for the atlas as opposed to the smaller sierra diffs, and the cost of the 9" sierra diff which does have loads of ratios available.

You can then weld the casing of that!