If it is smoking that bad and is a crank seal, you will have lots of oil in the pipe on that side. You should also be able to put your hand behind the silencer on that side, rev it, and have your hand litterally coated w/oil. I would take the pipe off and see if you can dump oil out of it before you go tearing into the bottom end.
White smoke usually means coolant. Unlike tranny oil, it takes a lot less coolant to make a lot of smoke. Do you have a cool head. If so, I would bet you lost an o-ring. But even if not, I would check your head gasket. A lot easier than splitting the cases.
So basically, pull the pipes and see if you can dump oil out of them. If yes, crank seal. If no, check the head gasket.