The lower arms should be parallel to the ground. The tie rods should be parallel to the arms. There are offset bushings available for the steering rack that lowers the rack. If that is not enough then you need a bump steer kit.
Do yourself a favor, and get the actual bumpsteer alignment done. When I set up the bumpsteer kit on my car with an actual gauge, I've read lots of posts where people would say that parallel to the control arm is good enough. In reality, once I've setup the kit for as little bumpsteer as possible, there was a 3 to 5 degree difference between the control arm and tie rod end. If you are not going to do it properly, might as well not do it at all.
Get the bumpsteer gauge, measure it, and dial it to your liking. Ideally most people go for 0 or as close as you can get to it. One of my friends who works for TriPoint, said that you can benefit from some bumpsteer though under racing situations. Like for example, when suspension compresses you can set bumpsteer for slight toe out, so your turn in is going to be a little better. At the same time that will also make braking a bit of a handful, so it's really up to you where to find that balance of speed and consistency.
On both my lowerd Fox chassis and my lowered new edge, the a-arms are not anywhere near parallel to the ground. They slope up to the outboard side on both cars. Now, to correct for bumpsteer the issue is having the balljoint and the lower steering end-link traveling in the same arc as the suspension articlates thought its entire path. If they don't, the steering will change alignment settings as the suspension articulates causing "bumpsteer." If you used the MM bumpsteer kit, their instructions recommend a "base" spacer stack which oddly, puts the tie-rod and bottom edge of the a-arm at roughly parallel to each other -there is no reference to the ground. At this setting, I've found it to be acceptable without actually bumpsteering the car (someday though).
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