Help Please!!

[72longbed]

Can any body do me a favor and take a measurement for me please? I need to get an accurate measurement from the center of one trailing arm to the center of the other at the rear most point with the truck at stock ride height. I need this measurement from a stock C-20, (C-10 might work too if they are supposed to be the same), 1971 or 1972.

Right where the two halves are put together, at the very back of the arms where its the butt end of the arm, from one seam to the other in a straight line would be excellent.

I've got to straighten out what the PO did back there to get rid of some massive driveline vibration and I thought I'd start with making sure the geometry is correct first.

Thank you,
72longbed