Stock ride height

[71Bowties]

Hi everyone. This definitely looks like the place to get 67-72 truck questions answered. I have a 1971 GMC C-15 that came with rear spring suspension originally and has been lowered via underslung leafs. I am trying to find out the stock ride height (measurement from ground to fender well lip or something similar) to be able to establish how low the truck is now. I like the ride height as it is, but am wanting to change to a coil spring suspension. The stock measurement would allow me to order the correct drop coils for the new rear suspension. Any help would be greatly appreciated.

Thanks