I've read many times that the 6.9/7.3 IDI are very good engines to run WVO...
On the other hand, it's apparently not recommended for the DD 6.2/6.5.
Many of the GM diesel guys tell me I'll destroy my IP pretty quickly (I have about 4,000 miles on WVO on that truck, and we logged some 20,000+ on a pre-TDI VW before that, no problems)... because there's no way to prevent some of the remaining water to get past my 600-series Racor filter into that Stanadyne IP.
I'm just curious to get you guys' opinion... this is actually a question that can be asked to both Ford diesel guys (pre-PS IDI) and GM diesel guys (pre-Duramax), and the answer should be the exact same!
personally, i burn WMO, but i'll pass on what i've read on the subject
water is evil. thats why we have a water seperator. but i haven't heard of it killing IPs so much as injectors. from what i've read, the water is prone to eroding the injector tips as it explodes into steam during injection. however, during its time in the pump, its still disolved in the oil to where it doesn't appear as a seperate entity.
there are a number of ways to settle the water out of your oil, and i would advise using one of those. the simplest of these is to leave the oil in a drum out in the sun for a couple of days or longer. between the heat and the time, the water manages to settle out onto the bottom of the drum. there are also a number of commercial options available, but that depends on your budget of course.
Water separating filters DO NOT and CAN NOT 'remove' water from WVO and ya can't 'boil' water out of WVO.
Water is heavier than VO, so it will settle out eventually. We typically warm the oil up so it is less viscous to expedite this process. I find there is little advantage to heating beyond 110-120*F. After turning the heat off, I typically let the oil 'settle' for 48hrs or more - then drain the junk off the bottom. At this point, a Hot Pan Test will verify the oil is 'dry' and I pump it thru FUEL FILTERS (10mic and 2mic) into my trucks. I have over 270k miles on VO between my (2) trucks and have yet to have the first VO-related problem. My on-board VO filters typically last 15-20k miles - or more.
Hot Pan Test: Heat a clean skillet to 350* or so and splash a teaspoon of oil in the pan. Any audible bubbles is a NO GO, and ideally you want to see NO bubbles. You can guesstimate the temp by smearing a little oil on the pan and add the test sample when the smear begins to smoke. (I just use an IR thermometer )
Also, VO does not conduct electricity. I have a friend who likes to say 'you can throw a toaster in there if ya want'. Many of us put a 220v water heater element on the end of an extension cord (110v) and lower it into the oil. A 220v element will produce 1/4 of the rated wattage at 110v.
I have H&S'd 1000's of gals of oil using 'discarded' (read: FREE) water heaters. I wire the lower element to 110v - using the t-stat - and then use compressed air to push the oil thru FUEL FILTERS (not water filters or socks/t-shirts/pillow cases/etc ) and into my trucks. Here's a pic of one:
Yeah, I'm on FTE all the time - but seldom come down here. This is historically not a great place for good info on WVO...
Both of your trucks will do just fine on WVO with a good conversion. You need completely separate fuel systems with the ability to prevent ANY WVO from contaminating the diesel tank and filter so you can completely remove WVO from the IP and injectors at shutdown. You also need to see VO temps of 160* plus before the IP/injectors to get good fuel atomization thru the injectors.
'Blending' and/or sharing fuel filters as well as not adequately heating WVO are recipes for a slow death to your IP and ultimately the engine.
Your engines are about the least expensive there are to convert. I can pretty much guarantee you will save money in the long run if ya make an investment in a heated, 2-tank conversion system.