4.125"
a 400 small block Chevy has a 4.125" bore.
get a big block or bore it 54 over
4.155"
4.165"
350 block, 400 crank. Main journals must be turned to accept 350 bearings. Stock bore is 377. .030 over is 383.
bore and stroke a chevy 400 smallblock.
4.125"
421 c.I.d.
4, and 1/8th inch.
4.125 inches
Factory stock, the 400 cu. in.
A small block 400 engine can typically be bored up to about 4.155 inches, depending on the specific block and its condition. However, the maximum bore size may vary based on the manufacturer and any previous machine work. It's important to consult with a professional engine builder to ensure the block can handle the increased bore without compromising structural integrity. Always consider the potential for overheating and other performance issues when increasing bore size.