James it can be bored to .040 with easily found and cheaply had pistons. .060 and then it gets harder to find pistons and you are at risk for a flexy block that will burn oil and run hot. In short .060 requires serious engine building skills that if you had to ask that question we can assume you don't have. Further, it takes more than an overbore to reach 3.0, you need a diesel crank and L24 9mm rods. I think on this list Bob Hanvey is the ranking expert on the 3.+ liter engines on this list. Ask him.