Driveshaft length

Professor Fate said
Normally you measure center to center of the u joints for factory shafts.
If you are looking to have a custom driveshaft made, check with your supplier as to how they prefer the measurements be taken.

Oh so that's how they came to 49.27 then?

Id rather not have a custom driveshaft made. Id like to save the money and go with factory one, just wasnt sure if it would fit.