Clive,
For what it's worth, I'm running my pump in the stock location for a 280, stock lines to the engine bay, then AN lines to regulator, to the rail, and out of the FPR to the stock return line. Filter before pump. I've only run a couple of auto X's and 4 runs at the drag strip with probably 1/8th to a quarter tank, but no stumbles at all.
Mike