Reportedly, this game was made as a kit as well as a complete game. We asked Ken Fedesna, Executive VP/General Manager over Williams/Bally/Midway from 1988 until their close of pinball production in 1999, who provided this detailed information:

It was referred to as GridIron II in all my notes to differentiate it from the original GridIron, so your assumption regarding this is correct. The first mention in my notes about this game was on 6/1/84 where we were trying to come up with a preliminary cost estimate for building it. A prototype build was released, but nowhere in my notes do I have the number of proto units to be built or what was built. On 10/5/84, my notes indicate that the proto cabinets and playfields were due in the following week. My notes also indicate that it was to use System 8, and that we were building 4 ramp assemblies with the motors we had in stock and had to get more motors to build more. On 10/12/84, my notes mention for the first time that we were considering making this into a conversion kit for Pennant Fever in addition to a dedicated version. On 10/29/84 (after the AMOA Show) we released 150 dedicated units and 10 Conversion kits for Purchasing to buy the parts based upon getting initial orders at the show for 150 dedicated games. Production was scheduled to start 12/17/84 at 5 to 10 per day. On 11/26 my notes indicate that production was still scheduled to start on 12/17/84. Then on 12/20/84, the entire production of this game was canceled and all parts on order were to be held until Spring to build more baseball games. At that time, our cabinet supplier had built 45 cabinets, and 60 backboxes and was told to stop. Same for Ad Poster with regards to screening playfields. If I remember correctly (?), the reason we canceled building this game was due to how late in the football season this game would be being introduced. At 5 or so a day, the 150 units wouldn't be completed until February 1985 when the football season was over. So, the reason there is no record of building any production units of this game (dedicated or kits) is because we never did build production units.