Wanted to do a quick update but found my old thread is now closed.
I guess that Bernie Sanders was right: “We’re all sick and tired of hearin’ about ya damn heater!”
Just a quick update, though......It’s been working fine down to around 40°F outside temps but seemed weak around the 30°’s, and seemed to be struggling to get the cabin up to 60°F. So I did two things, one I like and one I may re-do;
First, I added some pipe insulation to the flexible aluminum ducts moving the heat from the heater to the cockpit. These are 2” diameter tubes and the insulation has to handle the heat so the only thing I found locally was paper-wrapped fiberglass insulation for steam pipes. It is ugly, but it works and has self-sealing tape at the seam so it looks as good as anything, just not as cool-looking as the bare aluminum tubes. We’ll see if I ulltimately need the added insulation - I may pull it off for the better-looking, bare aluminum look if I now have enough heat output to work well without it.
The second upgrade was to increase the speed of the pump to supply more fuel and more heat. I can’t just turn a knob....I have to change a capacitor on the pulse board and got one that runs the speed up about 70%. I kept the same speed for the “low” setting, but now, instead of going up just 30% for “high”, it has a turbo mode.
So, with five minutes of garage testing (any longer and the heater exhaust stink get’s ya ) and using my IR thermometer, I’m seeing 150°F at the heater output (not fully warmed up), 107°F on the aluminum duct 3” away from the plenum and 92° coming out of the duct into the cabin (just shooting the thermometer up into the duct. Not the best way, but all I had). Quite a bit warmer than before. I was surprised at the temp difference between the steel, heater output plenum and the aluminum duct tubes, but checked it several times on both ducts and got the same readings. Maybe aluminum doesn’t directly conduct as much heat as steel?
Anyway, it looks like it should now be great for either warmer outside (low on heater) or much colder outside (high on heater) just by flipping a switch, and then the thermostat takes over. The only other mod I want to do, later in the winter, is to extend the heater combustion exhaust pipe a little farther to eliminate the occasional whiff of exhaust at long stoplights. That’ll be easy compared to changing the fuel pump speed. 
Love it....
