From 74 dart v8 spool mount k member to a 7o dusterv8 k member

The only issue other than motor mounts will be "IF" you have a factory anti sway bar. On the 73/ later K, which has spool mounts, the anti-sway bar goes INSIDE the K, and is shaped different

Of course they must both be V8 if that is the engine type

All other hardware will interchange.

The steering linkage is actually different, late, to early, but if you keep it all you can use "either group." That is, the steering box, pitman arm, idler and center link

Use whatever upper arms "fits your brakes" AKA large ball joints for disk brakes etc

To sum up, if both "K's" are same engine type, and IF you have no sway bar they will directly interchange