We have encountered the issue on several customers cars.
Step 1. install a phenolic spacer. The Aluminum ones will transfer more heat.

Step 2. if #1 doesn't work, ,make sure the fuel line is not routed low, close to the heat crossover.

Step3. Only have had to do this once, fabricate an 1/8" aluminum plate to block the radiant heat off the crossover passage from the fuel line.

Step 4. Set up a return line with a restricted orifice to get the fuel moving instead of sitting in the line above the crossover cooking.. haven't had to resort to this yet

block off the crossover.

Step 1 and 2 have cured most of the problem vehicles.