I have an a/c problem on my jeep cherokee 2000

I have an a/c problem on my jeep cherokee 2000 4.0L 6 cylinder.I change almost the A/c unit, compressor,filter drier,line hose,evaporator, only remain unchange is the condenser.I have converted the compressor with Mitsubishi Magna but new one, still my A/c wont work efficiently.Especially during hot weather it will only give 10 degree minus the ambient temperature.I suspect maybe its the condenser.Gauge are all ok it gauge 35-37psi.I have closed also the window of evaporator that giving outside air,I've also put 2 fan in front of condenser as mechanic advised because the condenser is making high pressure, air blowing from vent are all strong and ok but the problem not that cold enough..please advise..thanks a lot