Urvan master cylinder

[patrase]

Hi,
I am about to fit an Urvan master cylider - 15/16th size that i assume was originally designed for disk front/drum rear.
It is to go on to an Ej holden, that currently runs HK holden discs front and hr holden rear drums (don't know what size rear wheel cylinder though), with an inline VH40 booster.

Couple of questions:
Would some type of proportioning valve be helpful, if so what options - i have seen the wilwood one for $100. What about an HQ one(already have one of these lying around). Also what exactly does the HQ pressure valve/proprtioning valve do-it doesnt appear adjustable?. Or do you think i wouldnt need one?

Thanks

[dattoman1000]

Only proportion if you need too. As your only boosting fronts I'd imagine rears might be O.K as is. Depending of course whether you have the 13/16 wheel cylinders from a drum fronted HR or 9/16 off a disc fronted car.Its also possible you might need larger wheel cylinders....depends on suspension settings , tyres , load , and weight balance amongst other things.
HQ one is set at a certain pressure I'd go with the willwood adjust one if required as you can then set the amount you need to keep rear wheel lockup under control.