- Original SBC 400 displacement: 400 cubic inches
- Bore increase: .030 inches
- Stroke of the 350 crank: 3.48 inches
Using these values, we can calculate the new displacement as follows:
Cubic inch displacement = Original displacement + (Bore increase x 2) x Stroke * Number of cylinders
Cubic inch displacement = 400 + (.030 x 2) x 3.48 * 8
Cubic inch displacement = 400 + 0.06 x 3.48 * 8
Cubic inch displacement = 400 + 0.209 * 8
Cubic inch displacement = 400 + 1.672
Therefore, the cubic inch displacement of a SBC 400 bored .030 over with a 350 crank is approximately 401.67 cubic inches.