Retro fit 6.1 - parts check list

SOOO glad to see someone else going through this. I'm just now getting a replacement '72 Dart Swinger (lost my original due to my ex-wife).
My plan was originally to swap in a 5.7 Hemi, but now that the 6.1 and the 6.4 are out I'm weighing the difference between them.
I'm looking also for parts, I've heard of pre-modified K-members for this swap.
I also seem to remember a magazine article where they put a 5.7 into a 70 Dart and had to get some specialty headers in order to clear the steering column?
Plan is to get the dart, then start looking for an engine/tranny out of a newer wrecked SRT8 if possible, if not I'll start looking at crate engines/transmissions.
If I ever find that magazine article I'll post it.