Rossco,

If your fitting cosy calipures etc, you may want to upgrade the master cylinder and servo to a S2 one, it may be ok on the standard but the S2 has a larger core or piston or something so will cope better and will help avoid a sponge pedal.

I have a front and rear set up on mine and the pedal didn't even start to work until halfway down then is spongey before bitting the s2 set up stops this.

Also remeber, if you add a spacer, the sprigot ring in the alloys may not reach the disc so wont sit onto the hub, when you go to put the alloys on, you'll have to hold the alloy in place while you bolt it up. This also has oanother side effect, the wheels will wobble between 50 - 90 mph as they are not centred properly.

I had some custom ones made from some alloy tubing which sorted the job.

You may not have these problems but if you do atleast you'll know the cause.