Thee 2x3 back half is maybe 75 lbs tops and no advantage suspension wise so i would't care if it was round tube. If someone is building a round tube is like a moly cage. It sells faster and holds a b it more value.agree^^^^^
stock firewall and floor back to "B" pillar or rear of cab for trucks
2x3 square tube back half or OEM frame (no chassis cars)
steel rear quarters and roof for cars and steel roof and bed sides for trucks (other then OEM glass or aluminum vehicles)
All the BS pro-mod top sportsman cars need to be put into another class--then they can decide if they want small or big tires themselves.