Coolant leaking again !!

I’ll start by saying a few months ago my water pump failed . I had the timing belt and water pump replaced by a reputable mechanic on his own time . While replacing the water pump
He called to say that the block surface was pitted and that he could
Not guarantee it would hold he slapped some silicone on there and away I went. a couple weeks ago i am leaking coolant again . I decide to go different mechanic he said it was my intake gaskets and that the water pump was holding. thousands of dollars later after driving the truck for a few days I saw a small drop of coolant on the ground. I have traced it back to just under the thermostat housing. I also decided to remove the upper timing cover to inspect the water pump. From what I can see it doesn’t look like the pump is leaking at least from what’s in view. I tried to stick a mirror down there without much luck pretty tight with the belt still on. The mechanic told me to bring it in for pressure testing but I’m worried he’s going to
Charge me and arm and leg again and say it’s the water pump . In that case I’d rather take it to yota1 performance and have it done right ! What a nightmare on this 3.4 l I have owned it for 1 year 190k