Somewhere in my build thread under the old configuration with the big wing and TRW wheels, the car scaled at 48.5front and 51.5 rear. It came in at 2709. I was expecting FAR less, with a car that is essentially a caged shell. Now the car is in the low 2600# range with the lighter wheels/tires, lighter dash, revamped minimal wiring, improved fuel delivery system, smaler batter, no passenger seat/mounts/harness, no wiper assembly, and a few carbon bits. The LS1 will get the car down into the less than 2500 pound range, which is where I would expect the car to be.
Most guys get a shock when their Z gets weighed. Unless you plan out every piece of the build, you end up with a much heavier car than you planned for.
Mike