Update: Turns out the label on the box was incorrect, they'd sent me shocks for a Harley. The fitment notes were tucked inside the warranty so I missed them, but a call to Progressive told me what the numbers for the correct set of adapters should have been. ?
Unfortunately both Progressive and PartsGiant, the merchant from which I'd bought them, were out of stock on the 412-4205C shocks. I'm going to get a refund. So I'm trying yet another online shop, Speed Addicts.
Tom Herling