[Cipotifoso]

One trick I learned to clean up a sealing/mating surface is to use a small rectangular knife-sharping stone lubricated with WD-40. You can remove the old residue and clean up the surface by rubbing the flat stone edge over the surface. You'll need to remove the oil residue, of course, before the new sealants are applied.

Dave

(A version of this reply was also posted under "78 3.0 engine rebuild 2/11")