my 1987 f350 tows a 33ft 5 th wheel with a geo tracker behind and i have had problems with surging when going up hills bobcat pass 9800ft so i have put a carter elect pump on the driver side firewall with the in tank pumps delivering fuel to it i also put a large fuel filter and a purorlator pressure regulator bedore the carb i have eliminated the vapor regulator every thing worked fine untill this trip surging again i was told ford had two vapor reg one for fuel starvation problems does any one know