Does Replacing Stock Metal fuel rail really eliminates percolation???
 

My 1972 240z presents fuel percolation after 15 -20 mins sitting on traffic jams under 33°C temperature (Tropical weather)/ Panama. I have already installed some heat shield extensions to cover the bottom of the SU Carbs float bowls, isolating them from the manifold and have wrapped the stock metal fuel rail that is fastened to the cam cover with isolating cloth. Car starts to idle rough, tending to drop RPM at idle from 900 to 600. My next step will be replacing this fuel rail with rubber hoses as it was advised by a Ford Mechanic on another fórum! Will this really solve my fuel percolation problem?

it did not solve the percolation!