Sorry, but I can't really get to our 96 R/T 10 at present. But, as I recall, the High Pressure Port's Schrader valve is under the black cap on the line at the top outer right side of the filter-drier cannister. The Low Pressure Port's Schrader valve is under the smaller blue cap in the same general area but more toward the air inlet/blower housing and more forward by a couple of inches.
A high pressure relief valve exists othe compressor itself.
That's all that I remember...but I admit to being fairly "A/C ignorant".