The c body disc will not work , the 73 B body setup can work. The spindle is about 3/8" taller , otherwise everything is the same. Though there is sligthly more angle on the ball joint (I think) at full extension of the suspension there are no known, at least to me, ball joint failures because of it. I think Firm Feel has a modded ball joint for those to scared to run it ??? That taller spindle is used on F,J,M and R bodies .

If you can find a 73 up a body that has the same spindle as you would want on your 71 .