Piston ring end gap

You really need to compare what the ring manufacturer recommends to what the piston manufacturer recommends, if there is a big difference then call them both and ask them. Piston expansion is the most common way to set the gap but some rings expand more than others and if the gap is too tight, the rings can bind up in the cylinder or piston when it heats up and you can destroy your engine. Also nitrous, turbos and blowers make a difference on what the ring gap is suppose to be set at as does the type of rings you are using.