A 235 has a 3 9/16" bore size, and it can take a 60 thousandths overbore comfortably. I've even seen a few go 80 over, but I think that's pushing the envelope a little. A 60 overbore would probably gain about 7-8 cubic inches, just as a wild guess, not enough to really affect compression or power a noticeable amount, IMHO.
Jerry

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