Motor is hard to start after warm up

DID ANYONE READ THE BIT IN MORPAR MUSCLE ABOUT THIS PROBLEM they said that the gas we have to day is different than when our cars were new an the reed vapor is lower and the gas evoporates faster and the gas in the float bowl go away much faster this has been a problem for all of us in the local car club some of us put an fiber block under the carb. end of hot start problem but not end of problem after 3 to 5 days of not running