1966 GMC Cab to axle measurements needed

[wcstory]

I have a 1966 GMC 2500 dually one ton with a 133" wheel base. The standard 8' wheel base is 127", I believe. Could someone please give me the cab to rear axle center and what's then cab to bed spacing on an 8' fleet side.

I'm trying to decide between using stock 8' bed or making a custom step side box. Anyone have a 133" with a standard bed and can you post a picture (please). She is going to be a working girl , so I will be adding a light duty hoist under any bed I go with.