To weld or not to weld an fd diff

[leefitz]

Cheers infernal an dtuebuk, it looks like my next move is a welded 89-91 open fc diff. Im running solid engine mounts, diff mounts, diff brace and gearbox brace so the whole thing should be well tightened up. A few years ago at one of the tracks in ireland, one of the comps was won by a man running a welded diff so i did have the mind set that it would be of no disadvantage to me.

So my next question is, what dose it require to make an FC diff fit an FD casing?