With it's 4-Bolt main block and forged steel crankshaft, The ZZ4 Partial Engine is a proven winner. Used as the foundation for thousands of ZZ4 and Fast Burn 385 engines and the legendary ZZ430, The ZZ4 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