Esoteric topic: Wheel/tire combos for Rabbit in SM

I'm asking this question on Vortex too, but I figure I have at least as good a shot of someone here having some ideas.

I'm bench racing my 75 Rabbit in SMF. I don't want to butcher the fenders, but I can replace the fronts and keep the current ones in storage. So the basic question is: What the hell wheels and tires do I run on this setup?

I think 13" makes the most sense. I need to figure out a good balance between lowering and tire width with the constraint that I don't want to hack the car. I would modify for the best suspension geometry possible under SM rules, which should give me some considerable leeway.

Help?

Your pal,

Angus

in 13s, the usual set up is 13x8s or 9s with 225/45R13. There is a 255 now as well, but that violates your butcher clause.

In reply to Per Schroeder:

Thanks, man. I was hoping you'd chime in. Good to know about the 255s, cause I was very tempted. You know anything about the 235/45 Kuhmos? Little wider, lots cheaper.

And do you happen to know how much backspace I could get away with? Would adjustable coilovers give me any extra?