Instead of just standing back and simply observing this post, I'd actually prefer to chime in and educate you guys a little on this. Before you go jump head first into a DIY scenario, you should know a few things about the systems you are discussing. The '96 up Mustang systems are going to throw you a curveball or two - click here for further info:
Mustang assist unit peculiarities Also, note that the Olds G-body '80 - '85 only Type II assist units (without the external accumulator), should also be generally avoided (unless space constraints just simply will not allow for proper clearances of the superior external accumulator design)...