JJJ hello,
Welcome to the jungle, I don't have a lot of good to say about the grind on a 292 cam ( too much overlap for me ) but the lift is rather high for stock heads. I have seen a lot of broken springs, and dropped valves from 292's so I am happy to see that you got the right springs for it- this doesn't mean that you don't still have to check for spring bind, as well as seat presure of the spring. It should be 1/8 on your feeler gauge when at full compressed on the head.
Now if you have all of this & it checks out, and it happens again then I agree with streets....the studs are pulling up.
Good Luck, & welcome