Here's a thread I found on the newest Lexus V8 engines for the LS line (3UZ vs 1UR); it might give some insights into the next gen LC V8 (will it be a 2UR?). Note there is also a 5 liter V8.
http://clublexus.com/forums/showthread.php?t=239528
http://clublexus.com/forums/showthread.php?t=239528