440 swap

You cut the slant 6 saddles off your K frame. You weld on the ones you salvaged from the big block K frame. In effect, you are creating your own big block K frame. You use the trans mount to locate the assembly fore and aft, since the tranny mount location doesn't change no matter what engine/trans combo you run. You need to finalize/finesse the right/left location yourself.
The second option referred to reworking the engine portion of the bracket to fit the slant saddle, as another option to mount it. There are other ways, too- but all require at least a minimum of fabrication skills/ability.