Performance info for 170 CI

consider the desired power level desired vs usage and then put together the package of cam [then compression to match the cam]/carb/intake exh/gear that works in that usage range....or just a mix matched pos that could be fast if it only had this or that.

If buying performance pistons rated at this w/that cc.....you should check cc and correct to required chamber volume.

If dealing with stock piston or..
[the famous use stock pistons and mill the hell out of the block and head slant six build] short of the over bore, u know what you have to start [the pistons and rods don't grow taller] and can use the formula in conjunction with the calculator to get where you need to be after cc.
honestly though, if wanting more comp in a stock motor or cam change motor, just mill what you want within the realm of common sense...

I have 3 bone stock 225 heads 1 '66, 1 '67, 1 '77
I will measure them all and let you know how close or 'nuts on' they are.