Yes they can, what perplexes me is why are they too small? Something is not right, either the crank or the balancer. Find out what is the cause before you machine anything, what is the ID of your balancer bore and what is the OD of your crankshaft snout?
“She may not look like much, but she's got it where it counts, kid. I've made a lot of special modifications myself.”
— Han Solo