Does your handbrake use shoes or the caliper?
If its the caliper and theyre single pots theyre shit for the hydro wands,might be better off going for a set of calipers off a skyline.

I had this problem with my PS.
The handbrake was attached to the caliper and the pistons wind out instead of straight shooting out,if you know what i mean.
This means it takes ages to get them to lock under hydraulic pressure,theyre actually bettter on the cable,but still pretty shit.

I binned my rear calipers and discs and got a set off a gtst skyline,bolt straight onto the hubs,only thing is you lose the handbrake for parking.
For a drift car this is grand but for a road car then you might want to do a full z33/skyline brake setup swap.