Maximum length of RE adjustable uppers?

Just curious if anyone knows the maximum length the RE adj. uppers can be adjusted to? I am switching out to some fixed lowers that are a little longer than the RE's I have now and wanna get an idea how much further the uppers can go. Thanks.

-Mike

Standard formula for how much threads should be inside the tube is at least the diameter of the threads. For example, a 3/4" thread heim joint should be threaded in at least 3/4 inch.

Just trying to get an idea of how far I can go, especially since it is still mounted and I can't take it apart to check the length of the threads. I was trying to see if it was gonna be worth the trouble to shorten the fixed arms.

-Mike