Just throwing this out there, I'm having a high HP 414 built and was told at the power levels we plan on making (550+) a mechanical pump wouldn't be sufficient? We went with the Aeromotive in-tank pump that is supposed to be good up to 750 naturally aspirated.
If I need to use an electric pump I will, but am very hesitant to do so. Unless the pump is actually in the tank there is very little room back there to mount one that does not interfere with exhaust and other things.