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

i welded 1 x 2 x .100 req tube "Under" the stub frames @ front and back creating a box with the body. about 12-16 inches of overlap allows plenty of welding space on both sides. 67 Barracuda runs 12.6's 2 the track, leaves straight, no noticeable flex.