if you can match it to a model and build date and find the right guy looking for a dated match for his car it could be worth quite a bit. Had a chance to get a virgin one in need of a full re-build from a guy with heads and intake and he was looking to get a grand for it. ended up selling it in a package deal to a guy for way more than i thought all the stuff was worth, so i passed. Truth is any 400 re-build with aftermarket parts these days can be built beyond 455HO specs relatively easily. Most Pontiac blocks are drilled for 4 bolt caps, but the fact is we don't need them like the Chevy guys with most 455's redlining at around 5400RPM, with stock parts you will throw a rod way before you break a crank.