Indeed. Putting larger spacers on would destroy the arches and tyres quicker, and I would still need another set of wheel bolts, not to mention the interesting handling characteristics of a wider front end unless I fitted spacers all round.

I saw the sticky and they have the 1mm spacers fitted between the carrier and caliper.

In that case I guess mine are not as bad as that.

Some progress. Whilst making the disc spin I put a flap wheel on the edge of the disc ensuring I evenly attacked it (well, as evenly by eye!). Whilst they are tight they are not catching! I may well get the discs turned down 1-2mm from a machine shop should they catch in use.

However, maths must be out! According to so called sums on the tinterweb these should be a big improvement over the Wilwood Supelites despite the extra weight.

The pad area of the Wilwoods is smaller than that of an S2 RST pad and quite a bit smaller than a 4x4 Cossie pad. That is before you get to the piston size. If you go off Wilwood's way to calulate things:

https://www.rallydesign.co.uk/pdf/de...pot_brakes.pdf

Total Piston Area (TPA) = 3.142 x r x r x n

where
r is the radius of the pistons
n is the number (sliding calipers are assumed to have two pistons for this equation).

If you look at my Wilwoods the piston diameter is 34mm, giving each piston a radius of 17mm meaning:

TPA (Wilwood) = 3.142 x 17 x 17 x 4 = 3632mm (squared)

With the Cossie calipers it is:

TPA (Cosworth) = 3.142 x 30 x 30 x 2 = 5656mm (squared)

For the timebeing I have fitted TRW pads to aid in cleaning up the surface of the disc. They are barely worn but the Wilwood pads occupied very little space on them. I figured the TRW pads could do with taking a beating over something nicer! I shall report back on how the car brakes in due course over the 283mm Wilwood setup).

It will be intersting to see if the maths does add up...