Gen 5 Camaro External Bolt-On Tech - ZL1 Axels

Does any body know if the Zl1 axle shafts are stronger than the SS shafts? I want to upgrade my axels but I am not willing to drop a grand or more for what the manufacturers want for the aftermarket pieces.

They are stronger but don't look like they'll fit the SS rear diff. The ZL1 diff is cast iron and a lot bigger, I'm not sure about the spline count.
ZL1http://image.automobilemag.com/f/42130236+w750+st0/2012-Chevrolet-Camaro-ZL1-bottom-view-close-up.jpg
SS http://www.unitrax.biz/wp-content/uploads/2009/11/l_2048_1536_7AAAA75F-DB61-4D87-98B2-E2D0A080F4CB.jpeg

I did not know the ZL1 diff was cast iron. I will get with my nephew about the axles to see if they will fit the SS diff. He is a GM tech and has access to the GM service parts computer system.

Im browsing the interwebz looking for this answer myself!!! I dont want to drop $1200 for DSS axles when GM sells ZL1 axles for $644. Hopefully someone can help out with this!

zl1 axles have different spline count on both ends