I have the same problem in the single cab but only due to a slight case
crack near the oil cooler seals. The oil just oozes out from under the DH
shroud and makes a nice mess. I know about it but just watch the oil like a
hawk.  I'll bebuild it someday when I'm either rich and find the time, or
suck the motor and have to find the money and the time. Nothing like
planning ahead eh? I've been told tht these cracks ususally occur just in
front/tranny side (FIF) of the mounting studs to the cooler. Mine happened
to buck the trend and placed itself on the pulley side of these mounting studs.