I need to add a vacuum for my brake servo and wondered where the best place is to add it and what is the best way of going about it?

I have found a one way valve to stop any positive boost going in to the servo.

The servo is off a 205 gti (my car is a cossie engined pug) and I have added a 405 master cylinder as they are bigger. https://passionford.com/forum/restor...ng-gear-9.html