With it's 4-Bolt main block and forged steel crankshaft, The SP/ZZ Partial Engine is a proven winner. Used as the foundation for thousands of SP and ZZ crate engines including the legendary ZZ6, The SP/ZZ partial engine has a long history of performance and durability. Its forged LT4 powdered metal connecting rods and light flat top hypereutectic pistons ensure high RPM performance. Provisions for a steel roller camshaft and one piece rear main seal are "state of the art". Technical Note: Does not include camshaft, timing chain, sprockets, front cover, oil pump, oil pan, balancer, or flexplate.
Compression Ratio is dependent upon the combustion chamber size of the cylinder head that you use