To add to good suppliers and maybe more of interest for folk in the Yorkshire area Dunnings and Fairbank (Leeds) make and modify drive shafts. I have used them and they were efficient and reasonable.
I have the same heavy duty half shafts as in the pic and they cost £90(pair-me supplying standard yolks) including balancing
I have the Avon stickies too, just need more power to test them more
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Lee
Gardner Douglas Mk4, Ford 351C, TKO600, 3.31 LSD, Sidepipes, 15" wheels. Black, basic and buisness like.
My car pics