Systems, methods, tools, and kits are used to reducing shocks and vibrations in tools, including downhole drilling tools. In at least some embodiments, shock and vibration reduction can be enhanced within tools that include an annular chassis within a collar. Existing locations where a gap exists are identified, and clamps, alignment features, joints, or other components can be modified or included to reduce the gap between the chassis and the collar. This includes a tool in which the chassis includes a flow tube or other tool with an axis that is offset from the axis of the chassis. Minimizing the gap can include providing three-point contact, which stabilizes the internal component within the collar. In a downhole environment, a downhole tool that includes the collar and chassis can perform a drilling or other downhole operation, and the internal vibration within the collar is reduced.