Big block Valve cover suggestions?

Back when I was a machinist and had access to a mill, I would mill out much of the "pushrod bump" in the intake ports of 340/360 heads. But I would also mill flat the valve cover gasket surface of the heads. I only did 3 or 4 sets but I found all of them to have a high spot in the middle of both long edges. After I milled the gasket surface, it seemed to help them seal better with stock stamped steel valve covers.