They will swap fine. The only "issue" you may run into is the rear anti lock sensor in the rear diff. If your stock third has an electrical plug/wire on it, then you need to be sure the replacement one does too (otherwise, the rear wheel antilock won't work and the brake light on your dash will be on all the time). If your stock rear third doesn't have an electrical plug/wire on it, then the replacement third either can or can not have one (if the replacement third has one, you just don't plug anything into it and everything will operate fine).