Rear brakes lock up... front disc

Organics don't have the friction qualities of semi-metallics. Your fronts are greatly under braking even w 4 piston calipers . I run semi's on everything. The downside is you change rotors w pads everytime.
Make sure you manually retract the cable in its sheath. Basically, yank the shoe backwards away from the backing plate. That should fully slack the e-brake cables. The other fella was right also. Smaller cylinders make shoes spread quicker but require significantly more effort. No prob for power brakes but a real challenge for us manual folks. Good luck n be careful.