I have had my dart for over 8yrs and ran many 6.30 passes with the current cage. The guy I bought the car from built it and told me everything was done correct. Well I could tell the way he ran some bars it would never pass tech but I thought it was good enough for running the times I was running. One spot he did not weld all the way around was thick tubing so I assumed it all was and did not ever drill in it. I did add some tabs and those places were thick wall. But I bought a new motor that is going to be way faster. So when I started cutting all the bars out for the new cage about 30% of the bars were thin wall almost like exhaust tubing.