I am really surprised this didn't kick up

I'm a streeter. The speed limit is 65mph. I have about 437 hp according to the 93mph Eighth mile trapspeed. Yes on 1.03 bars, 1.125 swaybar, HD springs and shocks, and Big N Littles.
But no frame connectors, And since I never had them, I can't miss them. The only body mod is, I got the body guy to continuously weld the front floor to the back floor on both sides.
Could the car be stiffer? sure, but 90/95% of the time I'm behaving myself, so ......... My car won't be getting them anytime soon.
Besides, I've learned to appreciate the flex in certain situations; it's a street car, and was a DD for many years.