Mine is a 7.3 Ford-the easiest to convert-not knowing your motor any advice I can give just from the "basics" and what I've learned from 70k on my Jetta-and constant studying.
heres my set up:
My rig will just be used in warm weather-and the 7.3 heats the fuel by design-and the lift pump "will pump lard" as Ive read. I just have a oil cooler from a 5.3 gas Ford as a fuel heater.
Heres 10 pages of tank ideas:
http://biodiesel.infopop.cc/eve/forums/ ... 014102/p/9
You can have manual switches-although solinoid failures are very rare. Mcmaster-Carr has 3 way manual switching valves. You need 2 of them so you can can switch to purge.
I have a vegthem on my car-makes about a 20 degree difference in temp. I would suggest it.
The longer hoses you have , the more chance you have of things cooling off. insulate-insulate-insulate! Block off you rad in the winter to keep the heat up. I'd keep as much of the system close together under the hood-the engine only cares if the oil going in it is warm-not how warm it is 25 ft back. I would run the hot water from the engine to the filter->FPHE->tank.