K Frame question and steering

I have a 70 Duster that I am currently trying to swap a 360 in - eventually. I have a 71 Dart Swinger for a parts car and my plan is to swap the K frames from the 318 V8 powered Dart with the 225 /6 powered Duster. Should I swap the steering pieces as well between the 2 or can I swap just the K frames and have it all work. I know that I need to use a bigger Torsion Bar and was going to use the Dart's after I check to see if there is a size difference - going with the heavier duty piece for the Duster.
Thanks