I just got a UOA pump (Amsoil model, pretty much identical to Blackstone's) and am a bit confused as to the best practices when using it. My understanding is that I should measure the length of the dipstick for the tubing, mark it with a magic marker, then add about 6-8 inches to that length to reach from the dipstick tube to the pump. Then cut the end going into the engine at a 45 degree angle. Insert the angled end into the dipstick tube up to the mark, thread the other 6-8 inch end into the pump, attach the sample jar, and carefully pump up to the sample line. But how many inches to the dipstick length measurement should I add to ensure I draw from the middle of the sump and not the bottom or the top? Any other tips or suggestions on proper UOA pump techniques would be greatly appreciated! Thank you!