OK, Received the 3 new 84101B Fleetguard filters, and the new top rubber gasket ring kit (Top Cover) and assume the Rotella 15W-40 is the correct oil ? Any other recommendations ? We stock the Rotella 15W-40 in 5 gal buckets. Have never changed it but think might be a good time at 75K miles and unknown history before 50K when purchased this 01 320. Did the...