Rear Wheel Cylinder Spring Size

[69hemidaytona]

I have two different sizes of springs that go inside of the rear wheel cylinders on a 69 charger with 11 inch brakes. Does anybody know which one of these is correct?

[Dmichels]

All that spring does is press against the cup expanders  to ensure a good seal. Pick one that won't coil bind when the  the pistons are all the way in and one that is long enough to keep the cups expanded. The pistons do not move much when the shoes are adjusted properly.