Guys....need your input before we finish the cage. We have run the rear half with 1.75" x .130" DOM. We are now working on the front halo and downtubes, driver side "NASCAR bars" and front tie-ins through the firewall and to the shock towers.

What OD and wall thickness is allowed per NASA/AI rules for the rest of these tubes? Do I have to use 1.75" x .125" or .095" everywhere? I want to be safe obviously but don't want to add unneeded weight too.

Driver door/cage will look like this:
http://www.corner-carvers.com/forums...achmentid=8385
http://www.corner-carvers.com/forums...achmentid=8386

Also, we're adding a GM button style window net attachment (mesh not coarse net) that allows the mesh to fall rather than be flipped up. Passenger side is "X" braced. We will also have 2 horizontal bars (1 at top of dash level and 1 at or below steering column)...will mount an aluminum panel for gages, switches etc.. Bars will tie-in from front halo down tubes to shock towers. Can/ should the bottom bar be above or below the steering column?

Any other words of advice before we start welding?

thanks
Chris