If you’re getting your 70 or 79 Series ready for dusty tracks, creek crossings...

https://bravo-wiki.win/index.php/Why_Does_a_Clogged_Air_Filter_Make_the_Engine_Work_Harder%3F

If you’re getting your 70 or 79 Series ready for dusty tracks, creek crossings and towing heavy loads, a snorkel and towing mirrors are a smart place to start