From the perspective of those of us who tried to keep those 400's running back when they were new, it would be difficult for somebody to give me one of those things. Putting 400 cubic inches into a small block is a step too far. That 4 1/8" bore size makes them hard to cool, and blown head gaskets were a pretty common failure.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!