Jeep CJs are not noted for their quiet ride. Of course the driveshaft will still spin like that, but it is far from ideal.

BTW, the slip yoke splines are probably so worn it makes your driveshaft out of phase. Wind noise and knobby tires mask the symptoms, however.

Since we are talking about stock vehicles, the transmission and rear pinion is relatively parallel on my 300,000 mile 4-WD '95 Dodge diesel with original U-joints. The inconsistent front pinion angle is covered by a CV joint installed off the transfer case.