a/c dryer size

[kglowacky]

trying to finish/begin lol it seemed like roadblock after roadblock. The challenges with these trucks. I guess that's what make them fun. Anyone know for sure what size binary switch the threads are for an original ac dryer. I thought it was 3/8ths but now it appears not. I am converting to a 134 system and need to replace the switch. I need a female style plug just don't know the thread size and dia.

Also does it matter which male inlet you install it on the dyer? there are 2 possibilities.

UPDATE. The correct size is 7/16 20. Female connection.