About to start rear end swap... a few questions?

Well you didn't say what rearend your installing? I assume a 8 3/4? It is an easy swap, you will need to shorten your driveshaft. The axles aren't that big of deal either, if your using stock axle bearings, no big deal. If you are using green style bearings you may need to remove the axle trust buttons or block from the third member.