Dave, my tyre size is 185/65R15 on 15 inch wires which are 6J (6 inches wide)
I have had to put a 25mm sleeve on the steering rack to restrict the full lock and it doesn't hit anywhere now.
the issue is with 14" or 15" rims with tall tyres (ie 80 profile) where the fronts touch on the front chassis outrigger on full lock. On my Sammio I had 15" wires with 80 profile tyres and just never went to full lock and it was fine - but I was sitting in the car doing the MOT test and never went to full lock, so MOT tester never saw it touch!
The rears have plenty of clearance whatever wheels/tyres you put on (unless they are tractor tyres!!)
Anyway, I am expecting also to modify the wheel arches a little on the body to accommodate the larger tyres and give me adequate clearance, and hopefully I will check that out this weekend when I get my body. I will post pictures soon.
have a look at my blog (
www.mymigliaspeedster.co.uk) for details of my steering rack modification.
Cheers
Tony