Hi mitchbt,
See this post for a camper frame that could be close to yours.
https://www.sunlineclub.com/forums/f...-mc-18647.html
While the post above is for a single-axle Sunline, yours being a tandem axle, could/most likely is a slightly heavier frame, but not by a lot. That said, the steel frame is "not" considered heavy-duty. These camper frames are "part of" the camper system. The primary wood floor structure adds structural integrity to the frame, mainly in the form of anti-twisting. If you lift the floor off, the main frame is very flexible.
When you rebuild and re-arrange things, keep this frame system in mind and bolt the wood to the metal like Sunline initially did. Also, be careful about how the floor plan and weight are distributed. Sunline was good at creating a well-towing camper by where the wheels were located and where the camper's dead weight was to give a good tongue weight setup for stable towing. Cabinets/cargo areas are located where items are stored, and the weight adds or subtracts from the loaded tongue weight. Shoot for at least a 12 to 13% loaded tongue weight of the camper's total gross weight. 10% is the bottom limit, and one small cargo change can make the tongue weight go too low below 10%, and accidently become more unstable when towing it.
Good luck with your project; ask away if you have questions. Consider making a post with pics of your progress. It's always good to see Sunline restorations.
Hope this helps
John
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Current Sunlines: 2004 T310SR, 2004 T1950, 2004 T2475, 2007 T2499, 2004 T317SR
Prior Sunlines: 2004 T2499 - Fern Blue
2005 Ford F350 Lariat, 6.8L V10 W/ 4.10 rear axle, CC, Short Bed, SRW. Reese HP trunnion bar hitch W/ HP DC
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