[magnus_heydoc]

Thanks for the comments guys.

That description does sound like parallel now that you mention it.
You make some interesting points which may make me re-route. Luckily, moving these coolant tap in lines around some is not difficult so experimentation and getting some readings will be an option. You may be right that it should go to the FPHE first for the reason you mentioned and the fact that I'll have a 250w electric pad heater on the bottom of the tank which will allow me some more leeway. Similarly, I'm wrapping a copper coil around an aux. fuel pump back by the vegtank. The feed&return coolant lines and fuel lines are all in the same insulated jacket that heads from the aux. fuel pump to the firewall.

I'll have 2 thermometers. One by the IP (thanks for the fitting tip as I was wondering how I might do that) and one at my vegtank. For the sake of 20 bucks I thought it might be useful to gather more temp info with another probe. Incidentally, I'm wiring the 2 probes on a switch so I can use the one monitor (cooking thermometer from crappy tire), instead of having two on my dash.
It's apparent that there will be lots more crap on my dash by the time the valve switch and gauge (greasecar), two switches for heaters, a temp monitor and eventually a new tach, and boost gauge for a turbo (next project) get homes.
I hope to be wired this weekend.
Aaron