im looking for a CV driveshaft for my yj...i know i can use a front driveshaft out of a XJ but i was thinking of using a front driveshaft out of a 90 K-5 blazer it has the same u-joints, is there any reason why i can't or shouldn't use it?

Is it long enough not to bottom out when at full droop? Is it short enough to collapse at full compression? If so, then you have no reason not to run this driveshaft. Run it.

check out the front cv shafts on the older ford explorers, they're a pretty beefy shaft, and they are everywere. Marc