Drilling and tapping into the front boss area of a small block Chevy to supply an oil pressure line from a dry sump pump is not a common modification, and it's not recommended unless you have the proper tools, knowledge, and expertise to perform such work. This modification involves altering the engine's oiling system, which could have serious consequences if done incorrectly.
To ensure the safety and proper functioning of your engine, it's best to consult with a professional mechanic or engine builder before undertaking such a modification. They can assess your specific needs and provide guidance on the best approach, taking into consideration factors such as engine design, oiling system requirements, and the desired performance goals.
