I always Heat Cycle them and retightening them before even get the car back on the ground, on the BBK's I got about 1/2 turn more after that.
Stud size on mine was 5mm and so far you are the only one that picked up on the 1/2" and not 13mm on the nuts. But they are a metric thread so don't think it is 5/16 if you lose one of the nuts.
Also after telling people to put the studs back into the head many times still had people complaining they could not get the studs back in a few and had leaks until the were taken off and all the studs put back in (wonder why) or cut the end off the stud to get is started.
2013 V6 MCoA, Performance Package, Security Package, Comfort Package and Electronic Package.
Mods OEM Backup Camera, BBK Shorties, FRPP Cut and Clamp X-Pipe, Borla Touring A/B's, Airaid CAI, Axle Xchange 2 piece aluminum Driveshaft, Koni Sport Shocks and Struts, Vogtland V6 Leveling springs, Ford Racing 302s wheels wrapped with Continental 275/40 19's, JBL GTO 8628 6X8 in all 4 corners. 2013 F 150 FX2 With a 6.2 Boss