It would be horrible fight. Neither one of them would pull the trigger. They're actually really close brothers from all I've read. It would be 12 rounds of the lightest jabs you've ever seen from 250+ men.
I don't really like to watch them fight, but I almost feel sorry for them in a way. They're skill and accomplishments will be written off because of the incredibly weak era they happened to fight in. Their size and skill level alone would've given alot of all-time HW greats hell (particularly Vitali because he has an iron chin)