looking for good info for swaps

Any V8 K frame from 68-76 will work if you go that route. 73-76 have the nicer style spool engine mounts. If the 318/904 has the mounts on it, see which style: biscuit or Spool. Get0 the K for that style.

If you don't want to do a K frame swap, trans-dapt and shumaker make conversion mounts to use your existing K frame. I think the transdapt one only work with a biscuit style motor mount.