Build the roll bar high enough so the 5-point harness doesn't hold you sitting nice and upright while the roof collapses onto your head. Do you plan on wearing a helmet, also? Doing race stuff on a street vehicle doesn't make good nonsense.
Jerry
I don't plan on racing it, and building it for roll protection would be a lost cause, and probably won't wear a helmet, but that would be a great idea for any vehicle. I could build a roll bar behind the cab if I wanted to on this thing. The whole back-half of this 7200 pound truck is built from 1/4 inch steel plate.
