I see this NEW short block as a deal, you guys pay about $2K for a used empty block, or I see them go for that. Well this one is new, go find a new one.
I think he's looking for close to $7K maybe a little too high, I think $5k is reasonable based on previous selling prices.
Imho I would buy a new aluminum block for 5,000 before this one. Unless I had an original 62-65 Impala that was originally a 409 4 speed car and I needed that motor to complete it. (but I don't so it would be a new aluminum block for me)