a/c dryer [pressure switch

[kglowacky]

I am trying to figure out why my binary and low oem pressure switches will not turn on my compressor. (Bought one of each to see if either one would work)
Details. 78 Silverado factory a/c set up except changed compressor and condenser to 134. Bought new oem dryer. did change orifice. Can't get compressor to turn on with either the 134 binary switch or the oem 12 switch. I can bypass the switch and the compressor comes on and works great.
a couple questions.
1)there are 2 nipples on the dryer does it matter which one i install the switch on? have tried both switches on both nipples.
2) next there is a removal screw in valve in both nipples do they need to stay in or do I remove the one I have the switch on.

my pressures on my gauges are both in perfect range



UPDATE. After more study it is clear the switch I am trying to use does not match the dryer nipple on my new dryer. I need to either find the correct switch or get a new dryer. Anyone have any idea what switch I need. I bought the dryer on ebay and I cant find my purchase history on what it is for.

uploaded a picture. It looks like the nipple has a piece extending from the end of the threads that is stopping my switch from depressing /engaging the valve. Anyone have a picture of theirs they can share? I threw my old one out.