Amazing question. If there were a number I could tell you. If there is where would it be? I looked all over! The rear of the pan where the crank sits is skinnier than my block which leads me to believe that it fits early blocks with a two piece rear seal. Also, the front two bolts are a smaller diameter in the pan, where my gen 5 utilizes all the same pan bolts all the way around. Was hoping someone on here would know. I've only ever owned gen 5 454's and olds blocks.
