Ron, I have done this before and had good luck with emery cloth with a swirl pattern on various gas cars on the PP, not sure on diesel trucks though.
Not to steal Ron's thread here, but I also have a related question. I have had a OFE sitting under my bed for a few months waiting to have it installed eventually. My original goal was 80HP injectors with an EZ and my current mods. Now I have decided to do a 120HP injector and COMP box with an upgraded turbo such as a HX40 or the one from the group buy. My question is should I call SB and see if I can exchange the OFE disc with a FE with these new power level goals or will the OFE work ok? I also tow a 10K race car/enclosed trailer a few times a year, some are short trips (300 miles and others are longer 1200-1400 miles). How will the FE perform as daily driver and as tow rig? Thanks for the input.