One thing to check is the oil pressure sending unit is right beside the distributor. You'll need to check it first to assure the leaks not coming from there. If your positive it's coming from where the blocks china wall meets the intake then one thing that can cause it is crank case gas build up. Since tunnel rams don't use PCV valves then I'm guessing your using breathers in the valve covers. Make sure they are both open as if they are clogged it can build up pressure to the point it forces it out. You said you used sealant on top of the china wall, did you clean the top of the china wall spotless?
Did you use the gasket with sealant on it or just a bead of sealant alone?
I never heard of the intake warping due to the issue with the distributor, however it's possible that it cracked the intake and the crack is not visible to the naked eye.