Is there a better orifice tube I can use, tried 2 different ones and still can't get under 45* vent temps?

I have a 1989 Blazer and just got done putting a new A/C system in. I didn't like how it cooled with the white orifice tube, so I put in a Ford Blue one. This blue one makes it blow colder at idle, but the white one was colder while moving. The previous owner used Duracool(propane/butane mix), and it would blow 35*, even with the factory white tube! But with R134A and the ford blue tube, that everyone with old GM R12 systems use, it is borderline acceptable. Should I try one of those variable orifice tubes, or should I use one of those propane based refrigerants and keep the blue tube?