centering axle?

looking for good points to measure off of to center axle in frame. far as getting axle straight from front to back would i pull the measurements off the back of the cab to center of axle? and getting it centered side to side was thinking about takeing flat peice of metal and spanning it across c notch and measure to center or rearend. would these ideas work?

thanks.

you really can measure from anywhere you want. bed mounts right from the frame, old leaf hangers if you still have them. back of cab. have you already taken it apart? if not measure it now from somewhere and see if its the same on eachside. measure measure measure. centering the axle between the rails, once again you can measure from anywhere. just make it equal on both sides. measure from somewhere after the rearend shims/spacers. sometimes the axle is out a lil farther on one side. measure from the drums or backside of the backingplate if they look unbent. i hope that helps any.