Don't do it. There are a dozen calcs you can use, none of which will match the nameplate. The only time I'd feel comfortable with this is if their package stores, or something similar, and they use the same thing over and over.
OR.......you could run parallel 500s over to it......that oughta do it.
Now ya gotta decide to use fuses, or take a chance it'll accept an hacr breaker, ah go ahead and use fuses, their always accepted.