Are you running the oem reostat resistor type fan switch or the current 3 speek switch? On ours, I replaced the old reostat switch with the 3 speed switch, the same compressor as yours and it cools the car just fine (here is central Texas). With the evap in the 30's, the only thing that needs to happen is to be sure the fan is running at correct speeds. Also, check and be sure you don't have any leaks at the firewall and fresh air vents, letting hot outside air in.