You won't have to run 4:10's, I personally ran that cam varying between 3:55 and 4:56 in an E body. Yes, with the steeper gear it had more snap, but it will with a milder cam also. As for the oil, they have been pulling the zinc out of the oil for several years now. Flat tappets need that lubrication, especially with the higher spring pressures. They do sell additives