If I change out my pistons but keep the weight the exact same will this affect the balance of the rotating assembly?

 

No but you also have to make sure that the pistons and piston pins and rings all end up as a group coming out the same or a little lighter and then you could get by without rebalancing.

Some pistons are lighter but the pins and rings may be different too so look at it all as a package bfore you assume the pins and rings are the same but if they are you would be good to go.

 

I have reversed dome pistons now and want to swap for flat tops. I am hoping to use the same rings and possibly pins. I bought a rotating assembly and changed directionon project.