rrm,
You do NOT have this issue!
Your Sprinter is a 519/3500 series with the full floating rear axle (the axle just drives the rear wheel which has it's own bearing pressed and locked
onto the axle housing) so you have lug studs, which are pressed into the rear hubs which rotate on the rear hub bearings, not the rear axles.
You have dual rear wheels, but the studs pressed into the hub are long enough to accommodate both steel wheel or a pair of Alcoa Forged Aluminum wheels (so says Alcoa
since they changed their guidance on this a few years ago).
Your front wheels are mounted on the hub bearings and the hubs have the same studs pressed in as the rear hubs.
Only difference is how you install the off set on the wheels.
Fronts: offset goes in toward the center of the Sprinter.
Rear Inners: offset goes in toward the center of the Sprinter, same as the fronts.
Rear Outers: offset goes out so there is a separation between the inner wheels/tires and the outer wheels/tires.
319/2500 series Sprinters, like the one in life8dance's photo, with single rear wheels and much less load carrying capacity, DO NOT have the full floating axles but rather have bearings pressed right on the axles, which are then pushed/pressed into bores on the ends of the axle housing and retained by a bolted on cover/retainer.
This 319/2500 configuration DOES NOT incorporate dual rear wheels, and it becomes very important to have both types/lengths of lug bolts if you have
alloy or aftermarket wheels.
The short lug bolts are for the OEM steel wheels.....the longer lug bolts are for the OEM Alloy wheels. If you have aftermarket wheels, it's up
to the shop that fits them to get the correct length lug bolts, and provide you with the short ones so you can replace a blown/flat tire on the side of the
road.
Hope this helps,
Roger