596 head performance mods

According to your first post I see your wanting to run about .520 lift. That's no problem at 1.7" installed height using single springs that are properly selected. You just need springs that the rated coil bind is 1.13" or less. You only need to have the spring seats cut if you want to use dual springs.

Will I be able to get away with single springs with that much lift and dration at a 6500rpm redline?