World Products has introduced a new stock-replacement type block for the 8.1 liter big block engine. The 8.1 was widely used in marine, truck, motor home and industrial applications, and until now direct replacement blocks have not been available from the aftermarket. World's new block is designed to simplify use in typical applications, featuring stock style oil filter and oil cooler provisions to eliminate the need for modifying these systems. A stock crank sensor position is utilized, and stock style accessory mounting provisions, motor mounts and other fitments are all designed for direct replacement installations. Full water jackets between the cylinders of the standard 2.245" bore ensure proper cooling capacity, and bore sizes of 4.495 and 4.595 are available with siamese bores. The block is compatible with stock cylinder heads and other components.