USCT inboard kit question

Im getting ready to install leaf spring sliders on my 71 cuda project. Glad to see others are using them and seem to be happy with them. Check out the knock off ones if your on a budget. I think I got mine through amazon.
https://www.amazon.com/s?k=leaf+spr...x=leaf+spring+sliders,aps,98&ref=nb_sb_noss_1