Spitfire brakes

[S Garrod <S.Garrod@sheffield.ac.uk>]

I would appriciate any comments on the following problem with the brakes 
on my 1979 Spitfire.
The front calipers are fairly worn and need replacing, the problem is 
that someone has fitted calipers from a GT6 without changing the rest of 
the braking system, ie rear cylinders and master cylinder.
Should I replace the calipers with ones designed for a Spitfire or is it 
OK to use GT6 items without changing the rest of the braking system.

Simon Garrod.