The unveiling of the Camaro ZL1 sent many supposed Chevy buffs scrambling for their nearest GM history book to brush up on the return of this legendary nameplate. The man at the heart of the original ZL-1 program was none other than Don Yenko, who stuffed these all-aluminum 427 cubic-inch engines into the Chevy Camaro and Chevelle. Complete cars regularly fetch six-figures on the auction circuit, and complete engines can bring in tens of thousands of dollars alone.

Up on eBay right now is the most important part of any ZL-1 engine build, an original aluminum 427 bare block that, amazingly, has never been used. It even says “Yenko” on it. And the asking price will make your eyes bulge.

This block isn’t from any original Camaro or Chevelle ZL-1, but was rather cast between 1972 and 1974 with Yenko’s name embossed on the block, but without a casting number. This was a joint project between Yenko and GM, and these blocks were used in the Yenko supercars built up until 1975. These engines are rare enough as it is; finding a completely unused one is all but unheard of.

As you might expect, the seller is asking top-dollar for this hard-to-find piece of history. Unless you’re ready to pony up $29,500 (or near enough), you’ll never get your mits on this finely-machined block of aluminum. While obviously you would want to use this as a correct part for an original Yenko build, it might also make a nice show piece all on its own.

Think about this engine, enshrined in bullet-proof glass as a centerpiece to a collection, or maybe even a coffee table. It’d be one coffee table you don’t want to cover up with books.