Winnebago has a lot of information on your coach, all of it available from their product info page, at this link
According to the 2005 Cambria brochure, your E-350-based coach has the 306 hp V-10, with either a four-speed or five-speed transmission (more is better). All E-series chassis use the two-valve version of the V-10, as the three-valve version is too big to fit under the hood. The listed tow capacity of the hitch is 5,000 pounds flat-tow, and 350 pounds maximum tongue weight.
I am not a V-10 expert, but I believe the bugs were worked out of the engine by 2005. It would pay to have things checked out, such as the manifold bolt tightness.
2005 was the chassis year that Ford introduced the Tow-Haul feature. Your chassis manual should tell you whether or not your coach has it. I believe there's a dash light that says "Tow-Haul," too. Prior to that Ford had an overdrive feature instead of Tow-Haul.
Load the CR-V up with all your stuff and take it to a scale. You want it to weigh no more than 4,700 pounds or so when loaded. The 300 pounds left over is reserved for the stuff you have to add (like baseplate, lights, braking system) to tow the car, and a margin in case the scale reads low.