Measuring for 2 piece Drive shaft

[DCOOKE62]

I have contacted a local drive shaft shop about getting a new 2 piece drive shaft made. I got the reference points for which I need to measure. My question is I know that need to have the frame at ride height and "loaded" meaning that the frame should not be hanging. I currently have my cab off of the frame so do I need to put the cab back on the frame and take my measurements or can I just measure with the frame at ride height without the cab? Thanks for your help.