eBay Reground Cam

The camshaft timing events are more important than the lift. And I see they have a note on their listing that says you will have to pay shipping on a return that is not as described. I guess maybe that is going to be a red flag.
You can either run it with 1.6 rocker arms if that is option for you or 1.5 rocker arms, and IF the rest of the opening/closing, duration, and etc are suitable for your combination. Otherwise, you could try contacting them to see what they say about it. Maybe their listing was wrong on the lobe lift numbers. A Magnum engine would already have 1.6 ratio rockers from the factory, so if they ground the camshaft for that style of engine, the intended final valve lift is pretty close.