Switched over the refrigerant in my 86 monte ss to r134 picked it up yesterday from mechanic it worked took it out tonight and I am only getting 59-58 out of my vents. Compressor is running sounds normal. I don't get it.

 

If 58 or 59 degrees isn't enough to get it cold in the car...
you have some serious air leakage in the car..door/ window seals body panels somewhere..theres hot air getting in... maybe holes in the firewall or floors? I wish... I could get 58/59 degrees out of the vents...

That would make my vehicle like a fridge inside...lol