A 383 stroker engine is built using a 350 block combined with a Chevrolet 400 crankshaft. Other parts that improve the 383 engine's horsepower output include upgraded pistons, connecting rods and bearings.
The Chevy 350 series small block is considered the standard in domestic swaps. Its low cost supplemented by availability of parts make the 383 a cheap and effective venture.
A standard 383 stroker build uses the bottom end of a 350 engine and a custom fitted 400 series crankshaft. The crankshaft increases the stroke of the pistons to 3.75 inches as opposed to its stock rating at 3.48 inches. Although it is a considerably small difference, the longer stroke substantially increases the horsepower and torque output of the engine.