With the UVW Unloaded Vehicle Weight and GVWR Gross Vehicle Weight Rating listed for most of the trailers on the Heartland website you should be able to figure the CCC Cargo Carring Capacity or I've also seen it referred to as the NCC. (Net Cargo Capacity?) I did not see the UVW listed for the 3418 but it has the same 15,500 lbs GVWR as my 38 ft Torque 321 so maybe this will help.
The sticker on my trailer list the UVW @ 11,500 lbs, when I registered it I had to take in a weight ticket and it weighed 12,250 lbs with my gear (that's the added generator, fuel station & propane full, a basement full of tables/chairs/ect and all the linens/kitchen stuff & supplies) then if your boon-docking/tailgating you need to add 800 lbs for a full tank of fresh water. So I figure my CCC is the 15,500 lbs GVWR less the 13,000 lbs for UVW+Gear+Water = 2,500 lbs CCC. Which probably not by coincidence is the Cargo Capacity of the garage. Even though the GVWR of the 3418 & 321 are the same, the UVW of the 3418 is probably quit a bit less as it only has two slides compared to three which would mean the CCC is much more, my guess would be by over 1,000 lbs.
You may want to check and see if you can find a dealer website with the 3418 listed, a lot of the dealers include a picture of the weight sticker in the photo portfolio.
ADDED COMMENT: There is something I didn't take into consideration when I compared this orange to my apple. Cyclone's are 6 inches taller and 1,000 lbs heaver than a Torque. This I knew from comparing a TQ380 to a CY3800.