I'll add my vote to the "why bother" side of the camp. There is just not a need for power brakes in a car as light as the 1200. I personally like the "squeezing a brick" feel of well setup un-boosted brakes. Better feel and control when braking at the limit.

My old rally car had B310 front disks and rear disks off of what was sold as the 200SX in the US. No lack of braking or high pedal pressure here...

Yes, properly adjusted rear brakes with stock Datsun 1200 discs will have a very firm pedal feel. And do not take a lot of effort. The heavier cars (such as B210) can benefit from it, but the B110 is still light and friendly

Unless you're a 90lbs weakling, they just aint needed. I run S13's on the front, and U13 discs on the rear. With a standard 1200 M/C. The pedal is just right, with lots of feel, and tons of control.

i run s13 discs on the front and dont have one, the damn thing near lifts the rear wheels off the ground if i brake hard enough ... i went to a brake shop here in adelaide and the guy wouldnt give up the "fact" that you have to run a booster as soon as you go discs

ok, as for the hot engine with twin carbys not being able to make a booster work...thats bullshit

when i had the landcruiser 4 spots and r31 rear with a 7/8th master i didnt have a booster on the car and that pedal feel would be fine for on the track when you sorta know when you want to brake and stuff like that. but if you were starting to pull up on the street and for some reason had to stop alot quicker it was pretty hard to get the required force in the time you had

then i went to the R32 4 spot front twin spot rears with an r33 15/16th master. i installed a booster then coz i wasnt really that happy to keep driving with the old pedal feel. took the car for a test drive then realised that the booster was dead. that was just scary, having massive brakes but still having to be pushing the pedal as hard as i physically could to get the thing to pull up like a stock 1200(the seat was flexing a fair bit i was pushing back on it so hard)
got a new booster on it and to say it was a completely different experience would be an understatement. with everything the same brakes wise and a working booster it pulled up better than anything else id ever driven
and that was with an L20b and twin 40s, then the really worked L18 with twin 45s, both of which allowed the booster to work fine
and even with the CA thats on boost almost all the time the booster still worked fine

its more a thing of how big you go with the master cylinder as to whether you need the booster or not, if your still using the stock master or anything close to the size of it of course your not going to need a booster
but anyone that thinks that boosters dont do anything and are just for people that are too weak to press the brake pedal hard enough...come have a drive of my car with the booster line disconnected

c'mon nick of course you need a booster with your brakes! when your 1200 suffers elephantitis of the brakes it
suddenly isnt light enough to warrant not running one!

all you people with small brakes picking on me all the time

my point or points were more that a worked carby motor can make a booster work fine and that its more the master cylinder bore size rather than the car size that determines whether or not you need a booster

Pigdog
Have you run a vacuum comparison between a stock engine [almost any engine] & a cammy dual sidedraught equiped engine?

My little 1200 GX would pull 18" Hg at cruise & a fair bit more at idle [900rpm] which is quite enough to make a booster perform at its best.

The hot engine will develop adequate vacuum when the throttle is closed at speed but the vacuum signal decays significantly as the RPM & the road speed decline. Some hot engines are flat out making 5" Hg at idle although these would be seen more as race engines.

If the booster in your car provides a significant benefit then it should remain there as the vacuum signal must be adequate, but I wonder just how much better it would work with even more vacuum as you would get from a stocker.

As I had said, the Weber equiped Valiant Chargers didn't have brake boosters because of the low vacuum signal, so Chrysler used a different master cylinder to try & address the problem.

For what it's worth, a small bore master cylinder will provide more hydraulic pressure at a given measure of input [pedal] pressure, but will have longer pedal travel in order to displace the required volume of brake fluid.
In order to get an unboosted system to work properly, the pedal travel may end up being excessive.

A larger bore cylinder will displace a greater volume of fluid for a given measure of pedal travel, but will generate less hydraulic pressure for the same input [pedal] pressure.
With this system the pedal travel can be brought back to acceptable limits but the pedal pressure required to provide adequate braking may end up being excessive.

It's all a matter of balance between the two.

I agree. My old man has a VF hardtop with a nasty 340 out of a class winning marathon boat. You have to pull down the trans into 2nd or 1st (It's an auto) if you want any kind vaccuum assistance from the booster.
Otherwise it's heavy as hell. (The pedal)

well i would say my brakes and yours are comparable nick (pigdog)..

the only difference you have a bigger master and a booster as well

so conclusion...

if you want to put a bigger master cylinder you will need a booster as well

so new question...

why bother with either???