I think you are missing the point of how this works. The seal does not go below the retainer, you install the spring and the retainer on the valve stem, compress the spring and retainer, install the O ring on the groove toward the head and the keepers on the upper grove on the stem, and release the spring. Everything is now in it's proper place. The hat type seals fit over the stem and the guide, these don't work like that.
Fred


1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine