I dont think you’re going to see any “improvement” with that cam change. The change will likely be backwards and probably so small you won’t see it on the time slip. Have the heads been flowed? Also, I would not try to guess at a cold lash setting. Just lash em hot so it’s always right.
I have no idea if the head have ever been flowed and I wasn't provided any flow information from the previous owner. I'll ask him. How do you do a hot valve lash without having inconsistencies in the settings as the valve train cools down?