Frame dimensions 70 k10

[OhioPaul]

I've searched and searched for a diagram that shows dimensions on spring hangers for a k10 and have came up empty handed. I've looked through some old service manuals but they are just a generic overview of the frames. Does anyone know where I could find that info?

Someone has replaced the rear frame section of my truck and used Ford hangers on it and I want to replace them. I'm looking to figure out center to center of rear spring hangers riveted to frame. I know there are holes on the frame and they would be great to use if I had the original hangers , but I don't. I'm using a newer front of rear hanger. My shackles are stretched back so I guess I'd need to move the front hanger forward or rear hanger forward. Rear hanger is still original riveted to frame. My concern is moving the front hanger too much and having too long or short of a driveshaft by moving the front hangers.

Thanks guys.