The real price determiner is whether it's a big block 400, or a small block 400. The big blocks are worth way more than the small blocks.......LMAO....
Hey, the guy said it ran when parked, good enuff for him, so you should be fine with it. Beside that, he knows what he's got, even if it's a 350, probably a T350 transmission too......
Wait about 2 weeks, you can probably buy whatever he has for $100!! After all , he needs them out of his yard. Probably full of water too, if it's stored in the yard.
The whole mess might be worth $100.