I thought the inline 4`s is a modern intake? I thought if it was a dual 4 it was cross ram?
You could build one much cheaper, or buy one cheaper in new crate form unless you really, really want it for the #'s matching aspect.
I would have that thing torn down and inspected by a pro especially with that asking price since nothing would suck worse than buying a worn out hemi and losing $18-k.