tubing size

I'm trying to get my cougar up to snuff on everything to go for a 7.50 and slower cert. in the process i've discovered someone has scabbed in a pieoce of tubing on one end of the tube that goes from the uppper strut mount on the front suspension to the main frame rail in the footbox area. its a 1-1/4 piece thats in there now, just wondering what size and wall thickness is supposed to be there. Its a mild steel round tube chassis with the firewall moved back and aluminum floors.

IIRC any tubing forward of the windshield down bars/dash bar/lower foot bars ("firewall") on a 7.50 and slower SFI 25.4 or 25.5 cert is not checked/certified. So it can be whatever size tubing (OD or wall thickness) or any number of bars you want. It's your choice. Got pics of the bar?

None of the bars pictured ahead of the firewall are sonic tested (so no minimum OD or wall thickness requirements) on a 7.50 and slower SFI 25.4/25.5 cert. Use whatever tubing you want to use.