Make sure you check hoses and the thermostat housing. these have been many sources of leaks. Freaking owners out until the find the loose clamp check it over well you might get lucky, I did. Mine was the thremostat hosing the first time and when I thought ht eupper tank had a crack it was the upper hose seeping along the top of the tank.
I've had the upper hose leak after the uodate kit was installed. That was the only problem so I was happy with the deal. That hose is a pain to get fully on and tighten the clamp.
Think I need to find the upper hose! I was just searching the web for a new radiator...I've tightened and retightened everything else, but may have missed a hose (I hope!)