My , not directed at the op, but my thoughts in general.

Just keep driving around on those un-welded, no steering box reinforced K frames and think your handling is great. But then again one must go test to see what really works. It's an ongoing process and only works if you are paying attention to details. A car's rotation thru the turn or lack of rotation is the final test.

I built a large, heavy, fast flat handling rwd car that steers like a car with rack and pinion and rotates well thru a high speed turn...how's that?...Do you think just frame connectors and spring boxes made that happen?? Hardly, however they do contribute but the welded k frame is the key. Show results not conjecture and theoretical hypothesis.

So let me know what you learned, in the meantime I am going back to the porch and take a long nap in the rocking chair.