Make sure to get the flow control valve for the saginaw so its not so twitchy on the road. http://www.ebay.com/itm/like/400651963891?lpid=82&chn=ps&ul_noapp=true

For my 71 roadrunner, the very same car your running,
I have the boreson with the saginaw pump(with flow control valve changed) and a small ps cooler, smaller steering wheel(350mm), fast ratio arms, sector support kit and idler roller bearing kit all from firm feel. http://www.firmfeel.com/b_body_mopar_parts.html
I'm not sure if your planning to do fast ratio arms or not, but you should weld up the ps box support on your kmember or add braces to strengthen it up, make sure you use loctite on the bolts that bolt the boregson to the kmember, the sector support do help keep everything nice and straight and tight. I'm telling you all of this because my first go round with the boregson was not pretty- there was so much stress on the box with the faster ratio arms and the fast ratio of the boregson that I cracked my pump in two spots. And when I moved the steering from side to side, I could see the boregson move up and down inside the bolt holes that hold the damn thing in place. Now with everything I have, nothing moves and the steering is beautiful, My turning radius from lock to lock is about 1.8 turns, I highly recommend it!