Spring locators

I’m new to hemi’s, I’m putting a 5.7 together, working on the heads now I’m putting on comp springs 26918-16
I know I need the spring cups/locators 4709-16 do I need the spring seats 4705-16 too? The heads are at the machine shop and after I took the springs/retainers and seals they called and said they needed the locators
On my 20006 5.7 the factory valve stem seals and locators are one piece. If you replace the seals to a more traditional style, you will need the locator to keep the spring off the aluminum.