I know to all that read anything I posted was
1) Make sure all the studs are removed from the nuts and re-installed in the head before putting the headers on
2) Make sure you put the bottom nut on #3 (Last one on the passenger side lower stud) before tightening any of the other nuts
3) install the Studs for the Mid pipe in the header before you put the header on.
4) 5 Nuts on both sides can be done from the top with the box end or the ratchet box end between the tubes, #3 bottom was a 1/4 turn wrench flipper done from the top and #6 bottom was done from the bottom or the car
Your leak is in whatever nuts you do not have on, the bad thing is the studs will not go back in with the header on so it will need to come off. Also although they are a ***** to line back up the Mid Pipe does fit.
I also did mine in less than 4 hours by myself the first time and a bit over 3 the second, but I did remove my Stock Manifolds with an air wrench, and I also just used a 13 MM Box end and my battery and tray never came out.
BTW, I just used a 5MM socket on the studs with the 13 MM wrench holding the nut.
2013 Performance Package V6
2013 F150 6.2L Boss
Yes it is a Boss