Fuel Injection Pump 0402066721 3931256 For Cummins 6CTAA 8.3 Diesel Engine. Fuel Injection Pump 0402066721,3931256 For Cummins 6CT8.3 Engine Fuel Pump. For Cummins 8.3L 6CTAA. It is mandatory to check part numbers prior to ordering. Please make sure it is correct. If you don’t receive package over 30 business workdays, please notify us. We appreciate your Postive Feedback, and will do the same in return. We believe our items are so outstanding. All products are quality checked. Otherwise deal is final. We will be happy to resolve any issues you may have in a cordial and friendly manner.