The new dash and steering support is measured and welded in, connecting the pillars again through the middle, just beneath the bottom of the windshield frame.
Here’s where everything gets complex. The harness bar behind where the seats will eventually go is added and connected to the main hoop. A diagonal bar is added across the “square” created by the two pillar bars, the bar that connects them on top, and the main hoop. Diagonal bars contribute to sturdiness, safety, and rigidity by preventing more open segments (like this square on top) from flexing and twisting. Also, a diagonal bar is installed from one mount of the main hoop to near the top center of the main hoop. Another one is installed from the rear right support to the top left of the main hoop and also connected to the harness bar.
The cage is extended to the front suspension by welding in bars that go from the bottom of the pillar bars in the footwells, through the firewall, to just before the front struts.