The parts interchangeability of the small-block Chevy provides for numerous combinations; this results in varying displacements. The Chevy 350 engine provides a solid platform. Increasing the crankshaft stroke is a common way to achieve extra displacement.
The 350 engine gets its displacement from a 4-inch cylinder diameter (bore) and a 3.48-inch stroke. This factory combination has been used by GM for both standard and high-performance engines since the late 1960s. Many millions have been produced.
Using the 350 engine as a starting point, extra displacement -- up to and beyond 400 CI -- can be designed with the use of crankshafts of up to 4 inches or more stroke. The 350 block rarely supports strokes beyond 3.75 inches, because it lacks the necessary internal clearance.
The 363 CI displacement is attained by increasing the factory bore to 4.030 inches, and replacing the crankshaft with one that has a stroke of 3.562 inches. Pistons and rods with different dimensions are needed to correctly complete the combination, placing the piston at the exact top of the cylinder at the top of the stroke.
