Had to emerge and post, since I rarely meet Forum members in person.
It was great to meet you and your wife in the True Street staging lanes in Atlanta Dragway at CHP Nationals.
You both seem like very nice folks and enjoyed the chats.
I know another ZL1 had difficulties on the 60ft from poor stocker grip and inexperience, but still pulled out a 118mph with a similar 12.4+ET. Not sure-but something seams wrong with your run. The DA was around 3k which didn't help. The closed hood restriction hurts, but at least the ZL has some dissipation. Not sure if you looked at your ECTs at the line or had wheel spin further down the track. Overheated SC or bad gas? Somethings not adding up, but it may take a similar car owner/racer to assist better. Even with your good level of experience, sometimes its difficult to decern.
I ended up 0.022 off for my 3 pass average-not too bad since I hadnt 'Tried' to slow down a full 0.5s on purpose before to meet a Class time.
Ended up in the Semi-finals for 5th gen Cam. Couldn't pull it off, despite a better Tree RT, due to the high DA/ no reserve HP.
Was a good time, got 16 passes in, and met several new Camaro enthusiasts.
Take care and enjoy your two rides.