They are, and that is what I was going to do if can't get a spool.

But a spool is far lighter (and is unsprung, and rotating, mass, so as weight saving goes it's a good place to do it), and is pretty impossible to break (and I've killed a few welders in my time), so it would be great if could get one for a good price.

Spools for the US 7.5" diffs found in various fords are cheap and common, but I expect they're not the same as they're for the live axles in the back of Rangers and some Mustangs etc etc.