Yeah as lowlife99 said whatever you go with get the A-arms out or if you find a 71-72 donor the whole crossmember will bolt right in. I lucked out and got a whole 72 crossmember for $50 and the guy loaded it with his tractor. Blasted, painted and installed it and just got new pads and rotors from AutoZone.
Rubber brake lines weren't available locally so I got these off ebay
http://www.ebay.com/itm/71-72-Chevy-...item2ec7c35b43. They fit correctly on the crossmember connection and matched the length of the old ones that were on mine.
Alan