Fitting an electric pump may not be the answer, I had a problem recently in the Speedster replica with a 1916/44 webers/ Holley fuel pump etc.
http://www.aussieveedubbers.com/forum/viewthread.php?tid=30015#pid245918
It was a very hot day, and got stuck at the traffic lights for about 5-10 mins, just at idle. When I took off the thing just died the same as you explained. I had to put a wet rag around the fuel pump base to cool the fuel down enough to get pressure again. The pump was running just about dead headed against the regulator/carbs and putting lots of heat into the fuel in the pump.
This could be the same problem you are having even with a mechanical pump?
I think if you just rev the engine whilst you are staging and keep the fuel flow up (cool fuel being delivered from the tank) this will reduce the heat being put in and may solve your problem.
cheers
[Edited on 14-11-2004 by speedster356]