I run straight WVO during the summer and blend in the winter 10gal dino & 35gal WVO. I also run at least 1qt of ATF (new) in every tank (well most) for it's cleaning properties and have had no issues. Also when ever I change my oil (neighbors too) or the tranny I will mix a few quarts in w/ my batch of WVO when I centrifuge it, then polish w/ a 2 micron filter and run in my truck. The only fuel system mods I've done is the "Hutch tank mod" (got rid of the plastic crap in the tanks pickup) and I've added a coolant fuel heater, an electric fuel heater & a filter between the heater and fuel pump. Single tank setup and it works great. Single tank is not ideal; but didn't have the funds to do a 2 tank system.
'03 Excursion Limited 4x4 7.3l - Family Hauler - Alternative fuel; WVO blend.
Performance Mods: Superchips flashpaq; slotted/dimpled rotors; Zoodad mod; Steveracer mod; D.I.Y. intake; Terminator Engineering HPOP; FRx; HPX; AIH Delete plug.
Interior Mods: Alpine CDA-9883 Head Unit w/ SWI-JACK & iPod, Infinity & Polk 5x7, Sirius satellite, Alpine PKG-RSE2 10.2 Drop Down DVD w/ PS2 Slim.
I also HIGHLY recommend Clay @ http://www.riffraffdiesel.com/