I am considering a '91 F250 with a 7.3 to run bio-diesel in. I have found several sites that have kits to process WVO into bio. What does everyone here use? I really don't want to buy it at the pump to save on cost. Does it make more sense to convert WVO to bio than add a bunch of heaters and tanks to the vehicle. I am trying to find out from the people who have done it firsthand other than the sites pushing their product. Any help from those who have preceeded me greatly appreciated.