7 1/2" diff wanted with 3.9ish or 4.1ish ratio

[magpies]

Hi
I'm in the process of building a TVR S1 for tarmac rallying (Yes I know I do need my head examining)and am after a crown wheel/pinion set for my diff (3.6 LSD out of a Granny 24v) - any one got one? I'll even swap for my 3.6 ratio if need be.