My bet is that it will cost way more than 10K, and if i were in the market for a low deck all alu, BBC i would give shafiroff a call and order this:
http://www.ultrastreet.net/582_classic.asp with the aluminum block option... 14K, 582 cui, 745Hp and for 15.8K the stats read:825 HP @ 6300 and 720 lbs/ft Torque @ 4800 RPM...