The best option to smooth out the suspension of your RV that has tandem axle 8k Lippert springs is the Roadmaster Comfort Ride Shock Kit for 8k axles part # RM-2470 which was designed for your axle diameter and capacity. This would do a better job than a Timbren Silent Ride but worth nothing is that Timbren does not offer a kit for 8k axle replacements.
Dampening the suspension movement will do the most to make the ride quality smoother which is what a shock kit does. view full answer...
For a van conversion, I suggest the MaxxFan Deluxe Roof Vent w/ 12V Fan, Thermostat, and Remote, # MA00-07500K for smoke and # MA00-07000K for white vent cover. These options have a built-in rain shield and a thermostat on the 10 speed fan. This rain shield lets you operate in the fan during inclement weather without the need to buy an additional cover. This a reversible fan so you can either pull air from the van or draw air in. You can either control the fan from the pad located on... view full answer...
If your axle diameter is actually 3 inches the correct Roadmaster Comfort Ride kit is the part # RM-2460. If you had the 3-1/2 inch diameter axle instead you'd need the # RM-2470. view full answer...