6.4L MAXXFORCE 7 Ford Power Stroke Fly Cut and De-Lipped Piston Kit With Rings6. 4L MAXXFORCE 7 Ford Power Stroke Fly Cut and De Lipped Piston Kit With Rings Product Code: AA RCD 1740610002, AA RCD 1740610022, AA RCD 1740610032, AA The 6. 4L had issues from the factory with the stock pistons cracking. The Maxx Force 7 Pistons were designed for the International engine which are engineered to fix the issues that Ford had with the stock 6. 4L pistons. These pistons have . 080" deep valve reliefs cut into the piston to accept our