OK Guys,
lets think about the Physics here. You have a motor thats developing enough torsional force to twist the frame in opposite directions along the axis of the car. The K member is attached with 4 bolts. The front pair is past the mid-point on the forward frame arms. And the only major attachment point that can resist that movement is at the firewall. The K member will still rotate along the axis deflecting the sheet metal that is at its attachment points.
Think of an over loaded wheel barrow, you pic it up and it twists rather freely along its axis. Same thing here. On top of that the frame rails are actually two pieces of sheetmetal bent 90* spot welded to each other. That construction style allows for even more flexibility.
Its the same kind of movement we are trying to counteract with a sway-bar.
They work by transferring load from one side to the other.
After looking at the rad/frame attachment point, a simple vertical triangular gusset plate would do wonders if the radiator sheet metal was thicker.
But its to thin below the rails, to sufficiently resist the twisting moment to make any difference.
Ive seen the video and it makes perfect sense. I have also seen all the products up for grabs, and in all cases something is better than nothing.
One of the things I have learned through the process of building my car is that practical solutions can in the end limit your choices afterward. Think carefully
I will be making my own piece.
Andrew