Bigger master just means you have to use more force but push the pedal less distance

A small master means you can use less force (and therefore not need a booster) but the pedal will travel further. As long as you do not run out of travel on the small master then that is fine. This is the way i like my brake pedal

my brother put a 7/8th master in an escort (in anticipation of a big brake upgrade he never got around to doing), the pedal would not move more than 10mm and you had to brace yourself against the seat to be able to press it hard enough

the theory if you can be bothered reading it

So in saying that 1200rallycar would you think I should go for a little smaller master then the 7/8" Evan with my bigger brakes? Or would it have been better on your brothers legs to go the bigger brakes?

heys guys just seen this post and thought id ask a quick question, how do you remove althe boosters and is there any mods you need to do for brakes?

Sorry datrotor but you started to loose me when you said good quality and willwood in the same sentence , but that said willwood does actually have a relevant formula on their web site that can give master cyl size calculations . But you need a lot of info to fill in the formula , you will need to know front Caliper total piston area , same for rear , pedal ratio and desired pedal effort in newtons , while previous experience can give you a starting point some track testing is sometimes the only way to tune in the correct size

Wards I was under the impression wilwood is good which is why most race/drag cars use them?

They use them because they are cheap

The Datsun master can be had in many bore sizes
So start with the basics if you already have one and work up or down depending what your leg likes
My 1000 conversions I have used 11/16 , 3/4 and 13/16 on my cars
And one customer even used 7/8 for his
So you can tailor it to suit your needs
All suitably modified for disc brakes of course

And as far as working out forumulas... they don't take into account hose flex , pad compressability , flex in the caliper bodies , movement on the slide pins and a number of other factors... so can only be used as a guide

If every1 dosnt like wilwood what's a good brand?

you get what you pay for, if you cant find a OEM part that suits your needs , AP racing or Brembo are hard to beat , but they are not cheap

A good brand is Nissan -- Nissan make awesome 4-pot alloy calipers.

Nissan 4-spot brakes on 1200 strut

What have Nissan calipers got to do with a booster or not?