Subframe connectors for a driver/cruiser, necessary to weld to floor?

I’m not a welder or fabricator and I did my own 1 1/2 X 3 or was it 2 1/2 ; the width of rear frame. It turned out pretty good. Look at how I extended the square tube bottom on the front and back and welded that in for extra strength. I’m sure there is a lot better ones here from other members but this was easy and didn’t mess with interior.

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