With flames like that coming from under your bonnet, there's probably more to the problem that vapour lock
I got this a lot in my XD on hot days with my older carb/manifold setup. I'd let it sit for a few minutes, then it would be AOK.
The one key thing to help you is a carb spacer. This stops the heat transfer between the manifold and carb, therefore reducing fuel heat/boil and the resulting vapour lock.
DON'T use an aluminium or metal spacer as these conduct the heat really well! The best spacers are made from plastic or wood. I don't recommend you whip one up out of chip board!! Look on "ebay motors", I picked up a new four hole 2" job for US$22 +p/h. With your bonnet clearance, you'd probably be best suited to a 1" tall one.
Vapour lock gone.