Doc, it sounds like the guy had a great collection. But for the record, Mopar never sold a Hemi 6-pack.
Only the 440 6-pack, and 340 6-pack, that's it.
Hemi only came with two "in-line" 4 brls. on the street Hemi, and 2-4 brls. side by side on the Ram manifold on the Race Hemi's.
Doc, You're a Chevy guy, so I'll cut you some slack on this one.