Crazy. I know lots of folks that used UCF in the past with good results.
Using the equipment I have, I would reach in the freeze plug area and measure wall thickness at 12,3,6,9 o'clock of the spot. Average the 4 readings to get wall thickness. Measure pit depth. Subtract pit depth from average wall thickness and then come up with the remaining wall thickness.
I really think I just happen to have bad luck. I don't think they did anything wrong other than the freeze plugs didnt seem to be changed. The finished product is great. And they are great people to deal with. It just took some extra steps to get there. And I wish I had all my bolts. I still wouldn't tell anyone not to use UCF but for myself I'm just going to use someone local.I have used them. They built the head that's currently on my truck, they also built the head etc that Jetpilot ran. Must be having some issues these days.
The block I have cut apart measured around .260" thick by the rear freeze plug.