On my Duster after I put in the frame connector I noticed that I got a bit of flex in the front from the firewall forward. I added some down bars that are welded to the fire wall down to the front of the frame rails. This made a big improvement with the flex. Also my frame connectors are mounted to where the leaf spring were bolted to with a about a 10" X 6" - 1/16" plate welded over the frame rail and the connector to tie them together and the connectors are welded up through the floor.
Tonight I was working on my Valiant and I noticed that when I put the stands under the front frame rails and let the jack down that I got some flex on the nose of it too. I don't want to install down bars like I did on my Duster, just think it won't look right on this car. So I'm going to see if I can come up with some type of bracing to do the same thing that can't be seen or isn't as noticeable. My Valiant is being build more as a handling car. I do have a 1 1/4" round bar welded in the front from frame rail to frame rail under the radiator to help stop twist in the front.
Brent, why don't you try a similar forward bar on the tire side of the inner fenderwell? It might take a bracket that goes over the top of the frame rail or just a good weld on the outside of the frame.
If you go around the whole body and stich weld all the unibody seams together it makes a big
differance. We did this when racing the old 510 Datsuns. Do this on the frame rails between the
spot welds on the seam edges also. This works well on any unibody car.