Replaced my control arms today.
I now know how my right hand inner drive shaft boot was damaged.
During the16v conversion the motor was mounted 10mm (approx) lower so as to clear the brake master cylinder, this means that the inner drive shaft boot now is 10mm closer to the "sharp" edged control arm mount subframe bracket (see photos).
When the car turns its hardest right at speed the right hand drive shaft drops lower and the boot only clears the subframe by about 5mm.
However when I turn hard right in bitumen motorkhanas (I have been known to do it flat chat on the odd occasion) the drive shaft is revolving quite quickly, the right hand drive shaft is at its lowest position (end of shock travel) and the boot grows in outside diameter (from centrifical force), this is when it makes contact with the "sharp" edge on the subframe and this is what damaged my boot.
I attempted to smooth the "sharp" edge off the subframe today and hope that it does not catch the boot again.
I suggest that this smoothing (or trimming) of the subframe is a "must" and should be carried out both sides before dropping a 16v lump in.
I also consider that most drivers will not corner quite as hard as I do in motorkhanas.