I believe if your shocks are only going to be doing shock stuff and you have everything setup correctly so the shocks are not expected to be bump stops or limit straps then the factory mount is more than enough. If you plan to use your shock as a bump stop or anything else that will see high forces then I would build a double shear lower mount, all of these tabs are 3/8” only because that was the thickness I was cutting at the time.How you didn't go with 3/4" thick instead