I am trying to remove the old, non-functioning, block heater from my 300SD. I simply can not get it to budge. I have tried heat and lots of force. I did a little research and think I would rather have a tank style heater. These connect to a low part of the coolant system and circulate warm water. Here are some examples, http://www.kimhotstart.com/products/small_tank_heaters.htm. I would appreciate any ideas on removing the old heater, or installation of a tank style heater. I would rather not install an oil pan heater. Thanks in advance.

P.S. I am new to this list and new to working on these cars. In the last few weeks I have done tons of work on the 300SD and can say that it is much more of a pleasure to work on than my Audi V8. When I have finished bringing her up to spec I will post some info.