Alright, I'm new here and looking to recharge the R12 A/C in my 1982 Ninety-Eight Regency Brougham...I just have a simple question, in the pics attached, which is the low pressure valve and which is the high pressure? TIA for any help

 

If I recall correctly, under the caps the valves are different sizes, you will not be able to hook up your recharge unit incorrectly.