A 225 is 3.40 x 4.125stroke, for a 224.7cid total
To make 235 cid the bore would need to be 3.477. this is .077 oversize.
If one assumes a piston could be found at plus .080, the actual bore would be 3.48, and the final cid would be 235.4.
Whether or not the block would accept 80 over I cannot say; this is just the math.