Codes indicate it's from a 1971 El Camino or full-size, 327 or 350ci. No sign of bad threads or damage. Surface rust throughout but should clean up easy. It measures at 4.00", NEVER BORED, but will likely need a little removed to clean it up. A bit of a time capsule, I bought this ~2004 and it has followed me across the country across 20 years! (Always indoors and off the ground.) Sold the car it was intended for and no other projects on the horizon.