Sprucemoose said:
The J has six-bladed props versus the earlier Hercules' four, and the new aircraft also has a distinctive black section at the lower front part of its tail, which acts as an ice kicker."
I think that you'll find that the black section at the lower front of the fin is in fact the HF antenna (this replaces the long wire antennas on the K model). Also another easy way of telling them apart is that the K has underwing tanks whereas our J models do not.
Mac