Vintage Air System not too cool????!!!!

I have a Vintage Air GenIV unit in my early b body. Sanden 508 compressor, condensor is 24x18 and all other stuff needed for it is new. Granted, I got this about 3-4 yrs. ago, needed to have during the mock up stage, I got it vacuumed and charged about 4 wks. ago. I have a done my own vacuum on it with my snap on vacuum pump, and I let it run for a couple hours, disconnect the pump and watched the gauges for a few days and it was holding steady at 30hgs. So off the the a/c shop I go. They put a vacuum on it for 30 minutes, check to make sure it's holding, then fill it with r134a, (1lb 8oz) and it's blowing out the vents at 40 degrees. Low side at idle is 20-30 and high side is 200-250. The fans kick on at 250, and it comes down to 200, and repeats. The compressor is running doing it's job and all is well. The ambient temp that morning was 80 ish. So I take the car for a spin today, ambient temp is 107 and my thermamentor is reading over 70 out of the vent. I come home, switch to the wifes maggy, and its putting out about 60 ish from the vent, wtf is going on?? I check the VA instructions, and they call for low side pressure of 6-12 and the high side 160-250. So I'm good on the high side, but I'm high on the low side. Should I have them take out some r134a or add or what? VA says that the temp out of the vents should be 36-40 degrees.

Now VA had me check the heater control valve, blend door compressor, etc., and all work as they should. My dual spal fans pull 2700 cfm and cool the motor just fine. So I thought I would ask if anyone has a solution before I call VA in the morning. Thanks for the help guy/gals.