Bore it .030 over. A 350 has a 4 inch bore. When you go .030 over, the cid., becomes 355.
4.030"
You can bore a 350 .090 over, but the thing is the bore is so big that the cylinder walls are about a hair line thickness apart. In order for the engine to accept the bore and punishment of the shear power, the 350 Block must be casted with extra carbon to strengthen the block.
it is a 30 over 350
4.040"
355
A typical bore size for a Chevy 350 engine is 4.000 inches. A bore measurement of "sixty over" indicates that the bore has been increased by 0.060 inches, resulting in a final bore size of 4.060 inches. This modification is common in engine rebuilds to increase displacement and improve performance.
408 and it really cant handle that
20/350 = 2/35
Its a 355 cubic inch
60 over. any more runs too hot.
Most builders feel it shouldn't be bored over 4.065".