Update:
Z/28 suspension has arrived! I decided to not get to it before the weekend track day, though. I don't want to run into last minute issues. The crate was listed 300 lbs!
Headers were very easy to install, yet I've had such a hard time installing the rest. I was sure I cut the stock muffler wrong, and brought it to a local muffler shop. It turns out the x-pipe does not have the right angle the piping to get into the tunnel. If you take a close look, you indeed see a good angle in one side of the x-pipe, yet the other side goes flat and does not make that angle. This has pretty much erased my confidence in Texas Speed products. Yet, I have to say the header fitment seemed to be perfect.
The muffler shop will custom-build an x-pipe + mid-pipe for me tomorrow, so the exhaust will be tucked in. As is, I cannot install the bridge back, and I hate reducing stiffness of cars I go to track with.
By the way, the shop asked $350 for the custom-made piping (for perfect fitment). I found it reasonable.