I only started loosing coolant after the rebuild, so I doubt it is my oil cooler because I never touched that.
Opinions welcome I guess. I'm just so mad at the thing I almost could care less about fixing it.
Man, that aint happy days. As for blow-by, it has been reported that, even after a good and thorough rebuild, these engines will still have blow-by. Some more, some less.
I fully agree with the line of testing that you began. Compression and leakdown for starters. I am not sure that moving the crank is a good idea during a leakdown test. First, you will move the piston, thereby altering the pressure inside the cylinder. Secondly, if a valve is "just" closed, the touch of the rocker arm might be enough to make it leak. Cylinder should stay TDC and no movement. Others will chime in.
I would not tear apart what you already rebuilt, unless the facts do not leave any other choice. Look at the things you did not touch. Murphy is an *sshole that way.
Which coolant do you run? The orange/red truck stuff? That should be pretty decent for leaving crusty trails if you lose it externally (any hose connection or even the water heater core). You may only lose coolant when it is hot and fully pressurized (i.e. driving).
The oil/water cooler should be looked at. It can trap incredible amounts of crud and actually contribute to overheating. You need the two O-rings and the two gaskets (heat exchanger to cooler base and heat exchanger to lid). It is not hard to do and I bet the heat exhanger needs a good wash anyway.
Did you flush the block and the rad before you filled everything? I noticed that, aside from the crud that is in there anyway, the drying out of the water jackets during the rebuild seemed to "produce" more crud and stuff flaking off.
Also, the fuel setting on the IP might have been a good match pre-rebuild, but it might need to be tweaked for the rebuilt engine.