First off I don't want to get into a passing match with you, buti wasn't referring to the the halo bar.. I was referring to the lower frame rail... As it states in the 2016 rule book

MUST BE CONSTRUCTED OF 4130 NORMALIZED TUBING
TOP RAILS 1 ½” x .095”, BOTTOM RAILS 1 3/8” x .095” or 1 ½” x .083”, ROLL CAGE UPRIGHTS 1 3/8” x .083”
ROLL CAGE CROSSMEMBER 1 ½” x .095” UPPER RAILS 1 3/8” X .083”
REAR END SAFETY BAR HIGHLY SUGGESTED 1” x .083
Seems the rules were changed to suit a chassis builder to me...
As I said read the rules....