My issues are this, My 350 is bored .060 now and it's very hard to find flat tops for this size. but if I bore it to .068 that would bring it to a bore of 4.125 which is the same as a 425 or 455. My question is could I bore my engine on out to .068 and use bigger pistons? Do the stroke have to match? Is this possible? Flat tops for a 455 are alot easier to find and I want high compression. Right now my current pistons bring my compression to a 8:2

 

455 pistons have a different compression height and won't work in an SBO with stock rods. 425 pistons, however, are the same 4.125 bore as a 455 but the same compression height as the SBO pistons. These will work (if you can find them at a reasonable price).