get a snake cam and view the timing window on your phone while your under the truck to rotate the crank to set BTDC. That will be the best way to go around doing it efficiently. Adjusting valves should also set your idle straight assuming all other parts are in working order.Would valves being out of adjustment cause it to fail at idle like this? I’d rather take my time and do the valves myself since I don’t have a shop in my area that I trust my land cruiser with