The cab floor has two supports (front and rear) on each side.
Once you remove the metal at the end of a support, that portion of the cab is free to drop down.
Look at the distance difference of the cab to the running board supports.

Last edited by buoymaker; 11/25/2022 11:17 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."