Rocker adjustment

If you have to grid on the rocker you need to stop and fix the geometry. Here is no reason to grind a rocker. The geometry is wrong or they wouldn’t hit the spring, unless it’s 1.625 diameter, which I know it’s not.
It's a casting flaw. Even in the book How to Hot Rod your small block mopar they show where you clearance 273 rockers for bigger springs.