Jacob,

Dave offers great advice. This is no surprise since he just COMPLETELY rebuilt a 123 system like yours. What he didn't tell you was how thorough HIS conversion was. By adding a parallel flow condensor to what he listed, he probably has a 134 a/c that cools better than the factory R12 systems. After his project and the success of the project, I would consider Dave an authority on the 123 system.

The key is condensor capacity. When changing to 134 you lose about 15% of your cooling capacity. The only way to make it up is with more condensor capacity.

An improperly converted system is a great example of "pay me now or pay me later. I agree with Daves comment about your current problem likely being climate control rather than refrigeration.

Good luck,