K Frame Question.

I touched on this in the past but now need a definitive answer. I will post all parts I have.

The Car: 1971 Plymouth Scamp /6 225cid 7 1/4

The conversion to a Big Block 440 (1974 .030) 727 8 3/4

The issue:

I purchased a Direct Connection BB K-frame (spool mount) from a member on this site and am in the process of blasting and collecting parts. The K-frame is based on the 1973 K-frame. I want to do the brake conversion to the front. So I bought the Uppers from another member also purchased a set of spindles (1973) and I also bought a drive shaft again from a member on this site. I have a 8 3/4 A-body rear with 741 case and the open hi way gears. The question I raise is the suspension. I know I need to buy stouter torsion bars. I will buy the ones PST have and that should sort that out. Can I re-use all my other components? I.E Gearbox, tie rods, pitman, centre link? Or do I need to move everything to 1973 specs?
Thanks