And long term the bolts tend to work themselves out. The load on the connectors tend to wallow out the holes over time. But, if you don't have a welder or don't weld, bolting the connectors in place and then driving it to a shop where then can weld them in is a decent option. That way you don't need a shop that is comfortable with chassis work, just one that can weld. I've heard of guys taking their cars to an exhaust shop, because they usually have lifts and at least relatively competent welders.