Driveshaft length charts are nuts

It’s still best to measure to be sure.
the car doesn't have a driveshaft so where do I measure from? The endish, kinda of the transmission, the driveshaft doesn't go all the way and contact the tailshaft.

To where? eyeball the center of where the u -joints should be ??

Under a car with no driveshaft seems to be a lot eyeballing