If it is avalible from Ford, call Lloyd at Hammonasett Ford. Lloyd knows alot about whats avalible from Fords high perforance aftermarket programs. He owns A pro street Ranger pick up with A 429 interceptor engine in it.
I purchased a 460 long block form Jasper Engines out of New Jersey, around $1500.00 about 4 years ago it went into my 88 450 super duty, one big complaint with the 460 is you can't keep exhaust mainfolds from leaking, engine runs way to hot. Headers could be an option I guess but have not gotten to it yet.