A thing that would be even more interesting is a quad turbo setup since the smaller turbos are more easy to get and they can be mounted with less distance from the cylinder head.
Headers for a quad turbo would be very easy to make only two bows from two exhaust ports up to a flange and the turbo on it, done

.
But what would be the right turbo for a 540cid engine?
Any suggestion?
Thanks Hannes