Can you use any Honda 1.5 bottom end on my CRX d15b6?

No, not all Honda 1.5 bottom ends can be used on a CRX D15B6 engine. While some 1.5-liter engines from Honda may share similar components, there can be variations in design, mounting points, and compatibility issues that could prevent a direct swap. It is recommended to use a bottom end specifically designed for your D15B6 engine, or research the compatibility of the 1.5 bottom end you intend to use to ensure a proper fit and functionality.