Hello,
if you don't have ABS and you have an adjustable brake bias, i think that should work without an additional brake booster on your 1984 Alfa.
But be prepared it might need a lot of force on the brake pedal to brake. It also depends on your master cylinder and the brake pedal ratio. I would say just try and learn.
Over here in Germany we have VW beetles (the old ones) with adapted Porsche brakes. But they use a brake booster in general, because it's a lot easier and better to brake.
Regards, Markus