As said, the new pistons should be matched to their respective bores after boring then honing. It's very important to have a quality machine shop that has modern equipment and the know-how to use it. Decking the block, adding rod reliefs to the block if needed, final honing with load sensing equipment and good tooling are essential and the stroker components will be used by the shop to determine where to machine/cut. Are you going to assemble the engine yourself? If you take the block to a Machine Shop, can they order a stroker kit for you? It's best if you can get a stroker kit from a reputable machine shop because they can inspect and measure the new components for fit, finish and any assembly issues. Some components should be measured with micrometers and dial bore gauges. Accurate ones with repeatable readings are very expensive. Yes, you should get the engine block sonic checked, this can save you hundreds if not a thousand or more dollars, especially if you skip this test and have to do it again due to a split cylinder that had a thin spot in it. Even new parts MUST be checked carefully and then cleaned with hot soapy water then washed and dryed with solvent. The soapy water 'floats' the debris away, the solvent leaves no residue. Eddie