My guess would be that the fuel is vaporizing from the heat of the motor, and causing it to vapor lock and stall.
Try adding a section of 5/8" heater hose on the steel line from the pump to the filter, to insulate it from the heat of the motor.
That should cure your problem.
'87 YJ, 4.2L built and bored, 8" of lift, 8.8 rear, AX15/NP 231J, Tom Woods drive shafts, Flat fenders, 12,000LB winch, Custom bumpers, Rattle can paint job. Never completed...