Definitely need to check springs I.H. and check again for pressure. When hot they lose approx. 20lbs. on the seat so if they were close to 200 cold then that is biggest problem but not sure that's what the springs are so we have to wait.

Pushrods probably didn't help anything and if the springs were weak allowing valve bounce this would be amplified by the thin wall pushrods.

Galen, did you go to a thinner oil when you switched to Royal Purple? Thinner oils allow more spring temp too.
Brian