Help-K member swap 1975 Dart Sport

You can swap ALL of the suspension parts over to the 68. 73 and newer K member and suspension have many differences from the earlier setup. Including spool type engine mounts, different UCAs, center link, idler and pitman, sway bar, etc..

If your goal is simply to swap in a V8, it would be far easier to find slant 6 to v8 adaptor motor mounts. (Spool Type) Schumacher used to make them but the assets of his company were acquired by US Car Tool. Don't know if they are making the mounts though. You could try a wanted ad in FABO.