You can use a step bolt. These come in different configurations but they have a large diameter but thin head that works in tight clearances. It will provide plenty of support on that thin wall.
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2016 3160, Legacy, Sailuns, Splendide 2100 xc vented, 1 1/2" axle lift blocks, disk brakes. 2014 Ram 3500 SRW SWB 4X4 6.7 Aisin Mega Cab, EBC slotted disks and brakes, Titan fuel tank.
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