What's the possibility it's not 3/8-11 I made this mistake before, it turned out to be 3/8-11 When i guessed it at 3/8-10 that cost me , sometime to get what i needed to make it right The only way i new for sure was you try a 3/8-10 pin, then a tap , then the thread gauge lol Also, it's hard to judge anything from one picture, could be the angle that makes the pin look longer.Looks to be 3/8-10. 3/8 being the diameter and 10 being the number of threads per inch.
Is it sticking out a little over an inch? I'm counting 11 threads visible.