On finding out that contractor has installed incorrect size. Contractor has agreed to install 3T Raheem unit.
Will it hurt efficiency or damage my inside system? I understand newly installed coil is for 2T unit.
According to him 2.5T unit is not manufactured (which is not true per Raheem web site)

Rule of thumb the outside unit should never be a higher BTU than the air handler or evaporator coil. It can be the reversed with a 1/2 tone larger evaporator coil than the condensing unit. As far as I know all manufactures make a system equivalent to 30,000 BTU cooling.