OK. Michigan Truck Spring said that the XC-R chassis, if it has the solid axle, takes these on the front.
Bilstein 24-234498 | B6 | Shock Absorber. I had them send a pair for around $300.00 and another $50 for 2nd day shipping. They arrived more or less on time. Seems to be a good place to get them.
33' 2008 National Tropical on a Freightliner chassis.RVM#189