Dually slide-in?
I drive a 99 F350 dually and used to own a Lance 10' camper. You're right, its a tight fit. I upgraded to swingout mounts for the front jacks when I bought the dually but it only gave me about 1 1/2" on either side. Not a problem if you're installing the camper on pavement or cement pad. But if you're on dirt, and the gound is moist or just rained, the truck sometimes will slide on you. What a pain. I used 1/2" of washers under the front jack swing out mounts to gain a little bit more clearance. It helped, but you still cant mount the camper if the ground is damp. We sold the truck camper earlier this year since we dont go off road that much anymore and use a 24' travel trailer. I dont really think I needed a dually for stability when the camper was on, but more for better stopping power. More rubber on the road makes stopping 10,000lbs of truck and camper easier. If I were to do it again, I wouldnt go with a dually for a truck camper. Much easier to mount without the dually. Just my opinion. We used that truck camper for about 8 years. Drove to Alaska with it (6 week trip) and spent a lot of time in the great north west mountains.
Edwin
Leander Texas