CV joint is the name of a particular type of joint that allows you to connect two axles at angles to each other and still have them rotate. The 'constant velocity' bit refers to the fact that it's different from a Universal Joint, which does the same, but actually introduces small cyclic variations in speed on the driven axle. CV joints don't do that. Hence, this is a CVJ, not a UJ.
Also there is a mod on the Steam Workshop that allows you to do this, forget what the mod is called. Something like 'Enhanced Blocks'.