Help needed with brakes

[GMC]

Thank you Paul and Tim,
Had a look at it again last night and I recon I will change to a Subaru disc which will put the disc in another 12mm and if I machine the hub I should be able to safely machine another 5mm off it which at that point I will be getting close to been able to fit four pot calipers.
Unless anyone else know of a brake disc which has a greater height than the Subaru which are 57mm unless I go for the rear ones which are 67mm high, but are only available in 20mm thickness
Or maybe I should look at some custom bells which probably be the easiest way !

[Strat Fan]

I used a HiSpec 300 x 22mm off the shelf disc and one of their universal disc bells to move the caliper and disc as far inboard as possible to give maximum wheel clearance.
I think I did skim a little off of the aluminium hub but can't remember exactly now.
On the rear I used a standard Alfa 156 (front 285 x 22mm) vented brake disc as caliper clearance wasn't an issue with the Gp4 rear wheel.