Aeroflow Performance engine blocks are the ideal starting point for any street performance build that demands quality and precision at a reasonable price. Why start your engine build with a worn-out production block from decades ago that needs hours of machine work. When you can start with a new heavy-duty cast iron engine block that is a semi-finished bare engine block that requires very little machining to match your internal components. These brand-new aftermarket GM LS engine blocks are cast from premium high-strength Class 32B iron. The extra thick standard deck height ensures a reliable head gasket seal as well as allowing the use of off the shelf standard components such as camshaft, timing chain, oil pump/pan and oil filter etc. Featuring dual knock sensor locations in both the valley and the side of the engine block allowing either LS1 or LS2 style knock sensors to be used. Along with the cam position sensor in the rear of the valley which can also be blocked off to run the front cam sensor only. You can rest assured that these Aeroflow engine blocks have a great foundation for your next engine build.