I made this tool for pushing my piston rings into the piston cylinder, evenly, so that I can measure my piston ring gaps. Also useful, once the piston ring is pressed into the bore, you can reach inside and pull on the piston ring firm against the tool. my block piston holes were bored to 83.5mm, This tool should work on an 84mm bore as well. My miata is a 94 na. 1.8
 I didn't want to shove some busted ass old piston into my newly bored block twenty times so I made this tool, enjoy!   thank you for your support! let me know if your looking for anything else. my website will be selling these eventually. 

Tool name: PRGTP ((Piston Ring Gap Testing Pusher)) ;)