i recommend stones ...the steel carbide burr can cut to fast and then you will have a boat anchor ..no the efi manifold will not benefit from port matching to the head the manifold should stay smaller than opening at the head mounting surface ,the restriction there is the area inside the efi manifold ,needs to be cut open to enlarge it see pic
remove the bump in the ceiling of the intake runner only ..if you look in to the intake port from the window and use a flat ruler to find the hi and low spots remove the high spots in the runner .leave the gasket area alone smooth if you want , here is a article on the bowl area if you open up the bowl to much its a costly mistake
Porting Volume | Popular Hot Rodding Magazine Article at Automotive.com
Cylinder Head Porting Basics - Popular Hot Rodding Magazine