Both engines are fine choices in my book. My 2 cents is "Don't get weak in the knees and bolt a carborator on these fine looking Hot Rod engines". I like the clean look of the LT1.
definitley no carb for me. mine will look like this except my engine covers will be painted to match the truck.
http://i11.photobucket.com/albums/a198/ahsum/vortec.jpg