Consider what you are doing before making holes in your running board.
Not like this guy did in his newly painted truck (attached picture).
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Not Like This.jpg (290.67 KB, 63 downloads)

Last edited by buoymaker; 03/26/2021 7:32 PM.

"Adding CFM to a truck will only help at engine speeds you don't want to use."
"I found there was nothing to gain beyond 400 CFM."