Is my drive shaft too short?

I still have the original slip yoke that was replaced. My next move when I get the car back on the stands will be to pull the shaft back out and compare the two slip yokes.
I tracked the leaf springs part number to a 2005 MP catalog. "P4510268-9" are listed as A-Body XHD OEM Style Springs. Not much else info is given. I have to believe that the front segment is 20" but I will try to get a measurement when I pull the shaft back out.