Thanks Nuno!
I completed the install of the block heater today. It came with instructions, simple and straight forward, didn't take very long. The hardest part was cleaning up the frost plug opening. I unbolted the starter( didn't need to disconnect it ) and pulled it away from the block to give myself a bit more room.
The element fit perfectly. The literature that came with the block heater stated it was for Isuzu engines 4JA1,4JB1, 4JC1 and when I ordered it from the jobber I asked for a block heater for a 4JD1 based on the premise that a MF1160 which has a 4JD1 is the closest N/A model to my TA357( 4JE1 ).