RW, I'm using 5/8" heater hose for the coolant lines to the WVO tank. Nothing fancy. WVO fuel line is just 3/8" OD poly tube inside one of the heater hoses - same deal as original greasel setup and that shown in "from the fryer to the fuel tank". The '84 300D has had this setup, with a 12 gallon tank in the trunk, for about 2 years. I did not install and still a WVO fuel pump/boost pump. The stock lift pump has been sufficient, even though I'm pulling WVO through a benz pre-filter and a (heated) fuel filter ('85 Golf diesel filter with copper tubing wrapped around so hot coolant heats the filter). I did not change the stock lift pump/filter arrangement, so WVO goes through pre filter/VW filter, and then through lift pump and stock filter. No problems to date. I've run on WVO at outside temps to -15F in upstate NY...just have to let everything heat up first and suck that first bit of cold WVO (in fuel line from heated filter through selector valve to lift pump.). I'm about to convert my '83 SD and just for heck of it will install an electric fuel pump at the WVO tank with a separate switch so I don't need to run it all the time. In my case, I've found that filtering the WVO very well before it gets to the car is the key.

Good luck!

Fred