Using a plumbline as suggested, the gap to the sidewall (185/70) is 3mm all round, except that the rear nearside is 4mm. It actually looks less than that but my string is furry.
Also when sticking the tape measure over the tyre, the distance between the inner wing panel (wood), and the outer edge of the rear wing, is 206.3mm (10&3/8") Offside, and 206mm (10&1/4") nearside.
However, the 1986 inner wings may be different because the body tub dimensions changed in 1997, when it was made wider.
