I like to run a consist of three AristoCraft streamliners behind their FA/FB combination. These cars service the route from Lizard Lane to the aerial tram and have a modified figure 8 route that runs to as much as a 2.5% grade.
Anyone who has tried to run these streamliners over less than near perfect track has found they are prone to derailment. I attribute this to the way the trucks are mounted that allow no lateral movement, combined with the extended length of these cars. If the track tips to one side, that truck and the car above must also tip, and this action is transmitted through the body to the other truck, which may be on track that is tipping to the other side.
The trucks are held with two screws that allow for and aft pivot, but side tilt is prohibited by the shape of the mounting pads (flat on flat) as well as the underchassis detail. Actually even fore and aft pivot is limited if you run Kadees because if they are too loose, the Kadee “glad hands” can dig into the ballast causing derailments.
So, I propose to buy a piece of rubberized gasket material and use the laser to cut some washers to mount between the trucks and chassis. This would raise the body by the width of the washer, but would allow for tilt in any direction getting the underbody detail off of the trucks. If this raises the body objectionably, there is an established method to lower the body on the chassis, that many people do anyway.
I’ll try to get to it next week.