Super Stock or Stock Style Leaf Springs for my 69 Barracuda.

Ummm, I'm pretty sure all A-body front spring bushing bolts were 1/2" .... at least that's all I've ever seen ! Even on my 70 340 swinger ...

Look in the service manual for the torque spec. It even says that the v-8 cars had the 5/8" bolt and the slant cars had 1/2" bolts. They have different torque specs...