This is an air grabber assembly for a 383/400. The base is originally from a '70 Roadrunner, the lid is a 6 pack lid. There are 2 1/4" holes in the base for threaded rods to hold the lid on. I'm selling the whole thing as an assembly, if you don't want the oval 6 pack lid, sell it on ebay or craigslist (or here). It has been on my '69 for the last 22 years, since I have the correct one now, I now longer need this.