Good set of used heads from a mid 70's chevy small block 400. Were running fine just swaped for a better set. These are both cast #458642 Date codes areL 18and L 21. They have stock 1.72/1.5and include origional stock rocker arms and nuts. The engine ran fine but the heads could use a freshening up I think. The engine came from a 1976 blazer. 400 heads had steam holes between the cylinders due to the fact that the 400 blocks had siamesed bores. These heads have the holes but can be used on any gen1 sbc.offer!!!!!! PICK UP ONLY!!!!!!