AC R134a Retrofit

That's a 26° ∂T from ambient. Not bad, but you should be able to do better. What kind of condenser did you install? Stock type, or parallel-flow (manifold type)? What kind of fan are you running? Do you have a fan shroud? What have you done regarding roof/door/floor insulation and window tinting?

If you charged until you saw 40 pounds on the low side, it's likely the system is not properly charged. It's best to charge by weight. Charging by pressure can successfully be done but really only if you're very experienced and know exactly what you're watching for on the gauges -- it's not just any particular magic number.

You removed the EPR valve, good. But if you didn't install a clutch cycling switch, that's bad; it means your evaporator will freeze up with condensed water and system performance will drop way off.