[leegreen]

Have you played with tire pressure? It can make a huge difference in some vehicles. So can the tires themselves, all season type tread is more stable at speed than winter compounds and M+S tread patterns

If you have any easy way to get a couple inches lower on that link end try it and see. If it is not so easy I'd probably do some figuring with a full size drawing before starting any major work. Cardboard is cheaper than welding

Compress the spring to bump stop and measure how much the axle moves forward vs ride height and then how much it moves rearward with unloaded spring.
Break out a large piece of carboard and draw all the pivot points and arcs to scale, try and find a length and angle for the drag link that lets it match the movement of the axle for straight ahead driving.

there are lots of other opinions and experiences on this site