Here's a few pics...
This is part of a rear kit we are buttoning up for the 73-87 chassis. It will let you convert the leaf springs to trailing arms. We have a 71 rear end mocked up in it right now, but it will have the factory 12 bolt back in it shortly. This crossmember is for a 2-piece shaft (for laying frame)... the one-piece shaft crossmember is just a little different. More to come on this in the future.
Nate