Thinking about useing some on my truck , it is a 89 chevy S-10 4.3 with 275k on it, never hade a valve cover or anything off the motor does not use any oil, change oil about 9k to 10k, use pennzoil 10w 40 Dino oil, just wondering what the best motor flush would be, i would use the auto-rx but really do not wana change the oil 3 or 4 times within 5k, just wana one time deal, Thanks guys