If it is seized because of rust, that may not hurt the value too much, will probably still need bored regardless. If it is seized because the block is cracked from freezing or something else, it could very expensive to fix, if it can be? Years ago, a buddy bought a 427 block at an auction. It looked good. After together and in the car, he started getting water in oil. It had a crack looking from underside, up in cam galley area. Maybe worth fixing today, but he junked it.