Vapour Lock Issue
If you're running a square bore carburetor on a dual plane, this 5/16" thick gasket will help insulate the carb from some heat. I've had good luck with them...
http://www.manciniracing.com/hein4sqboe.html
Or find a similar one for your set-up if it's a different intake like open plane or spread bore. Find one that's at least 1/4" thick...