Since we'd mounted the shock tabs in a cantilevered position relative to the crossbar, we needed something to keep the crossbar from twisting under the shocks' forces. A short length of tubing, a bushing kit, and four stamped gussets came into play. The heat of welding can be counterproductive: these mounting tabs fit flush against the frame before we welded the gussets, so we had to make longer tabs. The distortion could've been avoided by either welding the gussets very slowly, a short section at a time, or by mechanically preloading the crossbar to counteract the expected warpage. 20/20 hindsight.