400ci big block in a van?

Ok gents, I know the SB mopar area, but my next door neighbor has a early to mid 70's dodge van with a 400ci big block engine in it, hes pretty much offered me the engine (it runs pretty good, no smoke/knock/noise) with decent oil pressure.
Are these engines good for anything? I severely doubt I could get it to fit in my 66 cuda, but is it worth keeping around for my next project vehicle?