As TSEJeepers stated, you need a driveshaft with slip in it... the CV part isn't necessissarily required but you must have slip in the shaft it's self. The whole reason you have a "slip-yoke" is to allow inward and outward movement of the driveshaft when the suspension experiences a shock (speed bump, off road, etc.). If there is not slip in the driveshaft OR in the yoke, you have a solid pice of steel connecting the driveshaft yoke to the transfercase yoke... When you hit a bump, it forces the driveshaft into the transfercase or into the pinion yoke, eventually one will give. You will 100% break the rear half of your transfercase, or destroy your pinion bearing if the driveshaft does not have a way of moving whenever the suspension experiences shock. At the shop I get people comming in all the time where the splines on the driveshaft siezed and wasn't letting their driveshaft expand and compress and it's amazing what that will do to a rear end.
The "CV" part of the driveshaft just allows for better driveline angles, most people dont know it but the most important part of the "CV" driveshaft they are putting in after getting a fixed yoke (SYE) is the part in the middle that allows the driveshaft to compress. Again, the "CV" part is just to allow constant velocity of the ujoints on both ends of the driveshaft which prevents wobbling and/or vibration.