I have a set of prc heads coming in this week. And I got a set of TD machine ls1,6 roller rockers. The prc description says factory rocker friendly. But TD machine is saying that the prc heads are completely different from factory. I’m thinking he could possibly be mistake for the 13 degree heads. Can anyone confirm this before I pay $800 for another set of rockers ( I’m not spending $1300 for another set as these were a gift and I didn’t want to spend that much anyways) or not and maybe bend a valve.