Body or truck bed floor cannot be raised more than 4" above top of the frame rail.

Max. frame rail height for passenger vehicles - 22".

Max. frame rail height for all other vehicles with a GVWR of:

• 4,500 lbs or less - 24"front and 26" rear;
• 4,501 to 7,500 lbs -27" front and 29" rear;
• 7,501 to 10,000 lbs -28" front and 31" rear.