I would eventually like to purchase an older Mercedes diesel and install a WVO kit. I have read that older diesel engines use rubber seals and that biodiesel, and maybe WVO?, can cause them to deteriorate more rapidly. Can anyone tell me how to know if an engine has rubber seals vs viton or whatever the newer material is? Also, is it only the fuel line connections that would need to be replaced or are there gaskets and other seals involved? How big of a deal is it to change all of that out? I'm mechanically inclined but I don't want to get into tearing down an engine or anything too labor intensive. Also, I don't want to end up spending lots of $'s on seals. Any advice is appreciated.