i lost my wheelbase! ahhhh

I took out my acle n spring mounts, ditched the i beams, and i think i might have forgotten my notes for where to relocate the axle/4 link. I am fairly certain i measured 37.5" from center of axle to the back edge of the rear cab mount x-member. Can anyone measer me where the axle goes from some point on the frame for me?
Thanks
Chris

oh yea i forgot, its a square body short bed reg cab truck.
Chris