If you are after a 347 how about a Ford factory built one.
I know of a Tickford T3 engine for sale at the moment. These are a factory built stroker motor that was the last of the Windsors and the most powerful the Ford factory ever put in a production car. They have lots of goodies in them including Heads ported by yella tera, roller rockers, billet rods, stroker crank, main bearing girdle etc. Built more for low down torque than high reving HP. They make 250KW with 500Nm of torque.
I've got one in my ute.