most of the rest of the country does not see -50 degree temps in the winter though.

 

Yeah, it really depends on the temperature.

My 93 with stock block heater:
At 20-30F, it'll fire right up into low-idle, evidently with the water being 120F.
At 0-10F, it'll fire up easily, but it'll be in high idle and won't produce warm air for a mile or two.

So, the wattage you need depends on temperature, and(I'm pretty sure) if you still have insulation on the under side of the hood. Mind /doesn't/ have that insulation, and you can tell by the hood being bare of snow in the morning.

Honestly, for the OP, just get a radiator hose heater(easy to install), and go from there.
If it doesn't do a good enough job, THEN you can add a second one somewhere else.

And, to all the replies about the 85 blocks being OK... please read where the OP installed an 83 block!

 

Does anyone that has the lower radiator hose style heater have a picture of how its set up? I have tried 2 different block heaters that replace the original (kats and zerostart) in my 86 6.9 and they both leaked immediately because they both require more depth than the oem heater which is no longer available. I tried a percolator style heater and it fried after a few uses but it worked really well when it did and could warm the engine in 2 hours. I think the lower hose heater is my best bet at this point i just dont know how to set it up.

 

Side question,

has anyone ever considered a diesel air heater like amazon has for about 200$?
https://www.amazon.ca/Monitor-Thermostat-Defroster-Controller-Motor-Home/dp/B07K861VNR/ref=mp_s_a_1_4?ie=UTF8&qid=1548947201&sr=8-4π=AC_SX236_SY340_FMwebp_QL65&keywords=diesel+air+ heater&dpPl=1&dpID=515ux6F9Q7L&ref=plSrch


it has flexible ducting that could just point at the block somewhere, and probably also heat up the engine bay to a degree. I realize it's not as effective as putting heat directly into the block or coolant, but 5000 watt output is also a ton more than any block heater.

 

When I need to use mine I've always had it on a timer, even at zero or below, 2-3 hours before starting the engine was all it took.

 

We use these in our 6.7 Cummins motors. They would be a lot more efficient then using an space heater.

https://www.eberspaecher-na.com/prod...t-heaters.html

 

100% agree, but definitely not 200$