Ok I have been pricing materials on building my cage and bumpers. NHRA specs for cages is 4130 1 5/8"x.083 and I'm not sure on what the DOM spec it but it is heavier. I do know that .083 4130 is stronger then .120 wall DOM. Anybody have any input on this before I order my tube? Also the .083 4130 is $.06 a foot cheaper then 1 3/4x.120" DOM from the supplier.