Anything capable of feeding a stock to mild 337 flattie with a simple inlet and outlet port that can run on 6V and be found in a Pull-A-Part yard?
Not from a yard, but an Airtex E8011 is 6V, I believe. Those can be had at Autozone, and several other parts stores. Or Summit Racing, if you have time to wait for delivery: http://www.summitracing.com/parts/atx-e8011