Hi all, I was going to put this in the 6.2 cause that is what I have, but figured it may also be pertinant to 6.5 as well since i believe they have return lines off the injectors too. Anyway, i did search first too. I read somewhere here where the good Dr. recomended using Ester (I think, pretty certain it started with an e) based hose material for clear return lines and was so good as to include a McMaster Carr part number and pages. I have some Tygon tubing, which is apparently good for "most" inogranic solvents, but I am uncertain how it would work with Diesel fuel and/or B100. ANyone have any experience with using the stuff for return lines? We have tons at work and it ends up pitched out all the time, so the price is right. Thanks in advance.