I finally got around to putting in the block heater on my 4300. Like Randy said breaking the block plug was interesting. I had to take off the muffler and alternator and loosen the clamp on the hyd lines. But all in all it went well. I pluged it in for a couple hours and thought I would check coolant level before starting and a bunch of coolant come out when I took the cap off. I'm hopeing this is normal, that pressure had built because of the heating.