What shop did you use and how much did it cost if you don’t mind telling?
So Cal Super Trucks in San Bernardino insisted on the SVC collars when I asked about the SDI top hats. They quoted me $700 installed and aligned OTD.
I used super trucks too. I spent some time with them asking about the collars vs. springs, never mentioned the SDI hats. His experience was don't do the springs unless I was going to pull and re-valve the shocks. In his opinions, the rebound isn't enough for the springs in stock form. So I went with their recs.
Looks like I was about $650 for the install and alignment.