There's is no way to increase bump steer with this unless you change the pitman/idler arm locations or ratios. The bend them down thing works because you are bending both ratios a close to equal amount. The drag between the two could "V" back to the rear bumper.
Loc: Minnesota, USA
Any concerns with bumpsteer are quickly verified by checking tow variances through the range of travel. I made the mistake of swapping to front steer rack and pinion with a modified stock k frame by an unqualified chassis builder and quickly learned the importance of performing the same check. Easy fix if it is introduced but important to verify non the less.
I had this problem on the original 2X3 chassis in my Challenger. I found out that the rack needs to be level with the steering linkage at ride height. It's pretty common sense. If the rack has steering arms that connect to the spindles at down angles, what happens when the suspension is compressed? The toe goes out. There's a little more to it but pretty simple.
The center part of the center link isn't going to have any effect on bump steer but the location of the tie rod ends will. Changing over to a '73 link from a '72 link will change the tie rod end locations so that could cause a bump steer issue. That is one thing I need to verify.
So I've learned a few things since I started this thread. I pulled the front suspension out of the Duster and got it mounted up on a fixture so I could work on it. I swapped in a '73 style center link and noticed that it is longer than the '72 center link. So that moves the inner tie rod points out towards the wheels which will reduce bump steer. So the '73 style center link should be better for bump steer than the '72. I don't think I knew this before.
The '72 tie rods do bolt up to the '73 center link but there is a lot of angle on the tie rod ends since the inner taper points down and the outer taper points up.
I'm going to put the suspension back in the car and see how it looks. If the tie rod angle is too severe then I either need to modify the lower ball joints so the taper points down, or just swap over to the '73 knuckles.