Ba Xr6t Diff...

[Mercury-BA]

G'day everyone. I recently bought a manual 03 BA XR6T and have instantly fallen in love with it. However, it appears I am having some trouble with the diff. The person who owned it before me installed a heavy duty brass button clutch in it, and when I go to release the clutch in first from a stand still, I get a lot of juddering and clunking noises from the arse end, once the clutch is fully released there is no problem with it, like wise when I am changing up or down gears, its just when I try and take off from a stand still. The mechanic told me it is a common problem with the BA's, just kick back from the diff, and that it was nothing really to worry about, and the fact that it is manual and has the BB clutch is the reason I feel it so bad. I previously had a BB clutch in my Nissan Skyline and it did not create any sort of noise or feeling like this. I am just hoping for a bit of advice on a few things;

-Has anyone experienced this type of thing before?

-Would I be better off putting a stock clutch back in it, or just putting in a bigger stronger diff?

-If it is just kick back from the diff, will giving my car sh*t make it worse?

-Is there anything else that might be causing this juddery knocking sound?

Sorry for the long post, just curious on the best course of action

Cheers

[Snaps]

Id be having a look at the diff bush and check that its not damaged.