The Sprinter GAWR is 3,970 lbs. front and 5,360 lbs. rear, total GAWR is 8,550.lbs.
Do you have plans for other additions? VC skid plates, winch on the front, or??? How much "stuff" do you plan to carry?
Many fully built and fully loaded Sprinters are at or over GAWR.
SMB's estimate for the empty van (I think they are a bit low, sorry again I didn't follow my own advice and weigh the van as soon as it rolled out the door) has you at 7,850 lbs. 8,550 - 7,850 leaves 700 lbs. for passengers, provisions, tools, fuel, gear and etc. It adds up fast.
I suggest you have Mark and Rob at Van Compass set you up with Fox shocks tuned for GAWR front and rear. I also suggest you spend the additional money for the adjustable shocks in the rear.
You will be amazed at the ride improvement and how well the suspension handles the weight. If you are anywhere near the San Francisco Bay Area come on over and find out how it feels.
“Flint” - 2016 SMB Sprinter 4x4 144" RB 150S w/ PH