need help with measuring for center shafts
 

I need a set of center shafts for my Mutant Maxx build. But I dont know how to measure for them. Do I measure end to end of the shaft or center to center of cross pins. Any help would be greatly appreciated

i would use metric measurement from pin to pin

Now do I measure from center of each cup? I need to know basically when I buy a 120mm dogbone are the cross pins 120mm apart or is the dogbone end to end 120mm

depends on manufacturer