You should never install used rings most rings now days have a plasma coating on them that helps them wear in faster with a finer bore finish. If you pull your pistons out of the bore it should always go back together with new rings and a new crosshatch. I usually go about .002 larger gap than minimum to prevent rings breaking as if they happen to get hot during break in the ends butt together and could break. Pistons should always be miked before being re used and remember the bore diameter will change when using torque plates (mandatory on Aluminum barrels). The dingle ball hone is excellent as it hardly removes any metal, don't use a spring hone as it will take several thou out of the bore which could mean oversize pistons. Snap on makes installation tools if your having trouble with the pin clips make sure to put a clean rag in the bottom end so if you lose the clip it doesn't fall down inside. Careful also about letting the pistons hit against the cylinder studs, cover them with plastic hose. When removing the heads be real careful about the head nuts as they should be removed gradually in the reverse sequence as torquing them up. These are a few tips, hope this helps.