Personally, I would weld the sides to the crossmember, as they are supposed to be. Why would you not want to? I imagine you will get squeeking noise & rust from the movement between them if you don't weld it.
The person who has nothing for which he is willing to fight, nothing which is more important than his own personal safety, is a miserable creature and has no chance of being free unless made and kept so by the exertions of better men than himself." - John Stuart Mill (1806 - 1873)
