Not mine. There's a guy on FB group Buick Parts & Pieces that has a set of 300 aluminum heads he wants to give away. They are located in Scappoose, Oregon. Free 300 Al heads
It still seems to be active. His name is Dave Ackelson. I've messaged him to see if he has an email or txt way to reach out. You have to be in the group to see it I suspect.