31. Last but not least...charging! Since I don't have the running engine in my truck at this moment I'm going to wait to charge the system. But if you are ready, make sure that the person that is charging it does a vacuum test sucking down the complete system and holds it there for 45 minutes. This checks for leaks that will not show in the first few minutes of vacuum. And let's face it, we want the A/C system to work when we want it to. Also make sure to read the instructions on how much R134a is entered into the system and if you need to add PAG oil to your dry compressor. When all is said and done make sure all the fans are working and put a thermometer in the center vent to see how cool the air is. In the mid 50s is about average depending on the outside temp. Good luck guys and gals and hopefully you can chill out while hot rodding.