Block heaters

[Member3768@domain.elided]

Hi all.  

Question:  It's getting to be that time of year (COLD).  I have a 1980 turbo
diesel Scout.  I have never had any sort of block heater on it before and,
other than "fogging" out all of my neighbors when I start in the morning, I
haven't had a major problem starting the truck.  It misses and smokes
terribly until I start to drive but it's always started.

Anyway, this year I'm planning on installing a block heater.  I was going to
either go with the Kat's or Phillips Temro electric core plug heater (both
400 watts).  The Kat's application states that only one heater is rquired;
the Phillips says that two are required.  My local supply house is "willing"
to make me a deal on a Phillips 5000 btu propane coolant heater, original
price $349.00; my price $121.00.  It plumbs into my coolant lines.

I have no experience whatsoever with propane block heaters.  Anyone out there
have any comments or ideas?  I like the option of being totally remote (I
have a very isolated cabin w/o electricity) but it's not required.  Also, why
do you think that out of two of the same type of electric heaters, one states
that one is sufficient and the other says that two are needed?  

Any and all comments greatly appreciated.

Thanks,
Gary