Air Conditioner low pressure port location on a 1987 ford ranger xlt 2.91 v6

[Nyx]

I'm trying to add freon to the a/c on my 1987 ranger xlt 2.91 V6 and I can't seem to locate the low pressure port, I've been told that the port is located on the metal lines leading from the condenser, but the lines on my truck are rubber and there's no fitting for the freon to be injected through. Is there anywhere else that I can put the freon or am I just looking in the wrong spot ?

 

[adsm08]

The low side pressure port should be on top of the drier. The high side port is over by the condenser.

Also, and don't take this the wrong way, if you are asking those questions you are going to do it wrong.

 

[kimcrwbr1]

Somewhere on the large tube going to the compressor?