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