(Newbe) 273 to a 340 and tremec 5speed swap.
Dare I say it but he's better off with a Mustang or something cheap where parts are in every boneyard...:)
Mopar stuff depending on what part of the country you are in isn't on every corner and its definitely not cheap.
id bet a running 5.2 Magnum from a used part yard is over 500 dollars ( not a pick a part)