Recently had head shaved and replaced (about ten days ago) and am now seeing a creamy cocoa colored sludge in radiator but no water in oil. What could be the cause?
You have some oil getting into your cooling system. This can be caused by a bad head gasket or not properly torquing the heads to the block of the engine.
When oil gets into the radiator it gets emulsified by the water pump and the end result is that it looks like what you have described.
Take the vehicle back to the shop, they will have to own this issue as they did the work.
They will have to replace your head gasket, make sure you head is completely flat and not warped and ensure that the mounting point on the block for the head is completely flat to ensure that this will not reoccur again.
best of luck