Originally Posted by 1006 Deluxe
Instructions said to try and acheive the same front fender measurement or slightly down.....snip
If by "slightly" you mean around a 1/4", this should be ok.
With your GM truck avoid having your front fender height drop below it's unhitched with the WDH engaged, doing so will compress the front suspension stops thus creating a notably hard ride and poor steering characteristics (been there, done that). The GM owner's manual also states only return to it's unhitched height.