I'm having issues with a Lennox 7.5ton 410a heatpump split system. This system has a dual evap coil ran by a single circuit compressor. My run pressures are way of at 60 low side and 310 high side, I have checked the lineset and expansion valves for any restrictions and could not find any. I'm not sure if my valves are sized properly, they are both 4ton and were installed during installation. Are these the proper size??