Intake Porting/Machining

I would defintely port match it with the correct gasket and more importantly make sure the ports line up when the intake is on.Alot of intakes require some milling for the ports to match correctly since there alot of variations between the block and heads depending on milling ect.I couldnt give a h.p. estimate but just think how badly it would hurt performance if the ports are out of alignment and the air is having to tumble off of the heads intake port opening.