If you want to do something different, go for the cubic inches and build a 415 cubic inch monster out of your block. Check this out:

www.speedomotive.com/500_hp_maxi_mouse.htm

377's are better for road racing or circle track racing that 383's which are better for drag racing (According to Chevy High Performance magazine article a couple of years ago). An extra 38 cubic inches more than a 377 is like a major power jump. And the amount of torque an engine like this can make is considerable and you won't have to run it over 6000 rpm to do so.