Iam thinking of getting rid if the standard sierra master cylinder and fitting a balance bar and and two brake cylinders one for the front and the other for the rear with remote reservoirs anyone done this ? If so what size master cylinders would you used for both front and rear

A lot depends on your caliper piston sizes. What calipers do you have now?

willwood 4 pots on the front and standard sierra on the back

I assume you have Dynalites on the front, in which case 0.625" front and 0.7" rear.

There actually powerlite , 1.38, 35/.50. If that makes any sense

35mm pistons are the same as the Dynalites so those sizes should be a good starting point for you.

Cheers for that

Just out of curiosity more than anything else - what are you hoping to gain by having a dual braking system?

Phil

i plan to hillclimb and sprint my mk ....some motorsport disaplines call for a dual system ....its safer and gives an easy way of adjusting brake bias

and it also allow fitting of the right size master cyclinder to suit your caliper front and rear

I was going to suggest fitting a brake bias valve instead but if you require a dual system for some disciplines of motorsport, then you don't have this option........

Phil