Thanks again for the replies. I was looking the online pic of the cage and trying to see where the back unbolts. I can see the overhead tubes in the roof halo have bolt flanges.
For it to be BITD legal where did you have to cut it off? Do you just sleeve chromoly into the old cage above the dash area and tig it together? Do you leave the rear shock mounts? Or do you cut off everything above the suspension and motor mounts?
BTW I believe that when it comes to strength that tube diameter is far more important than wall thickness. In the same material I'd opine that a 1 7/8 at .083 is probably a hell of a lot stronger than 1.5 at .090. I thought in the past that BITD tubing standards were advisory rather than mandatory.
In any event I wouldn't race this thing off the showroom floor, I'm just saying that perhaps adding braces and Xs could be an easier option than chopping it all up if BITD would let you. Keep the pics coming!