Match intake to heads?

I have always matched the ports to the intake gasket on the heads. On the intake I match the top and sides. I leave the bottom of the intake untouched for anti-reversion, thinking if the air flow tries to sneak along the bottom of the port it will get kicked up by the step. The Mopar Performance manual says the best flow is on the top and divider wall side of port. Every time I do a set of heads I swear I gain 2 mpg???