OE CV axles typically won't fail because the driveshaft goes first. Once the driveshaft is upgraded, the CV's become the next weak link and typically break at the axles' transition on the shaft. A broken CV axle can cause thousands of dollars in damage before getting the car stopped. Don't risk it, BMR's heavy duty CV axles use custom billet CV joints and 300M axle material. The axle itself is 1-3/8" diameter compared to the OE 1-1/16" and is capable of handling 800+ RWHP.