Fitting challengers

[bongo]

I had some on my old car with no arch liners and some 3mm shims and standard bolts worked for them. Did look a bit gash though being set in at the back so I went for some 10mm ones in the end and you can get extended bolts online if you look. In fact, I'm pretty sure mine came from a company in Notts and will try and find out but it was a few years back now.

Fronts can go straight on though

EDIT - RoadRunner Motorsport is where I got mine from though can't remember the size needed
but they should be able to help you out.