Like Mike said, I have a small block,and a big block cam with very sharp grooves cut at an angle to cut their way over the high spots in the bearings, Ive done thisto more than a dozen over the years and havent had any issues. SOme I have to cut, some feel great when I drive them in. I have 2 cam drivers, 1 is a OE mopar special tool, and the other is a after the market unit, and I have to say for mopars I like the OE one, you just have to wrap the drivers with black tape to keep from scaring the bearings.