Engle valve springs

Engle says the 606LS is for the 3/8 valve stem, which is what they sent me, according to the label on the package. I just don't like the way they sit on the valve spring. The retainers do not snap into the spring the way I thought they should. I wonder if they have a 909 LS retainer, and the "909" stamp was put on the bag upside down?

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