Do you have to have a modified cross shaft to install a 4.10? I ordered my gear from GERRacing.COM and it said nothing about it and when I spoke to a person in parts he said nothing about it, but when I look at some other sites it says that for the 4.10 that it's required for the install. Is this necessary? I'm getting my gear installed soon so I wanted to double check that I had all of my parts.