42rle, 3.73 gears, 33x12.5x15 tires. Cruising at 60-65 mph (about 2500 rpm’s) overdrive on oil pressure “normal”. Switch off overdrive( now running at 2800-2900 rpm’s. I can see the gauge slightly move up(1/4”). Switch on OD and oil pressure goes back to normal. Is this OK or should I be...