Boosted or unboosted brakes

i`m currently running a MKII escort in hillclimbs,sprints etc and the cars brakes dont seem up to the task ie not pulling up all that well.Possibilly i`m missing something.Any suggestions for improvments would be welcomed. On the front i`m running cortina front vented with skyline r33 calipers with EBC reds and on the rear contina vented with subaru calipers with EBC pads.This is all working through a pedal box running 7/8 master cylinder for the fronts and 3/4 master for the rear brakes.
Should the brakes run a vac booster or not ?
Should the brakes run a vac booster or not ?