top hat screws

Seems like I did see one at one time but not sure I am going to guess you can go with a bigger size not sure what they are now but make them as fine a thread as you can not much there especially in a high flow valve very little material there, on a talon or ss would be no problem. I tried to see what size Airforce uses I am thinking from checking mine I have mine out and don’t use them got my top hat set and loctited the threads and don’t use the set screws if I need to move it I just heat it up a bit a lighter will work to break the loctite down then I can move it again if needed anyway looks to be a 3-48 set screw they are so small I used a mag glass to see it and tried to compare it to a tap I have maybe someone will let you know for sure it know it is a size 3 by micking the tap and set screw but the thread pitch is very hard to see 🙄