Don't recognize it myself. But sometime those numbers can just be core numbers for multible grinds. You can measure it with calipers to get a idea of its size. Or you can degree it in the block and know exactly what you have, both duration and lift. Calipers will only give you approx. lift. But even that is telltale. If its a old .500 lift cam, duration would be around 245/250 @ .050 most likely.