I don't know the Edelbrock part numbers, but they have two versions of that head, the CJ and the 427. The picture is of the 427 head's chamber. It may just be a wrong picture as the description says chamber is 72cc which is the CJ size. The 427 is 76cc. May want to ask Summit if it is the correct listing.
Btw keep in mind that is for one head and says only one in stock. Unless you just need one you would need to find another and with edelbrock shutting down its old headquarters and reorganizing could be a shortage of castings for a little while.