IMPALA WHY!!!

Hello. First timer with a situation. I recently replaced my upper and lower intake gaskets after a plenum explosion (fuel regulator). I followed all recomended procedures in the replacement, put the engine back together and fired it up. Everything seem to be going my way, with the exception of a persived "miss" that I attributed to a less then good looking injector that I re-installed anyways. After the run up I was ready to drive down to AutoZone for them to scan for the "miss" when I checked the oil and discovered it to be over full with the beginings of the white death. I have read other threads that state that this is a normal byproduct of the gasket change, drain, refill the oil and life is good. Is this true or should I tear it all down again and see if something went wrong i.e. I screwed up?
Thanks!