Oops, sorry, I saw dial indicator and not a dial bore gauge. You will need a good micrometer to set it up and if you use it for bores you may need a 3-4" and a 4-5". If you are just measuring bores to check for taper and don't have to be super accurate you can use a dial indicator to set it up. If you are measuring main cap bores you need to be quite accurate and would need a micrometer. For fairly close measurements you can use snap gauges.