[incoming]

My neighbor with a very hot tuned 408 was having the exact same problem. He had a flat piece of aluminum 1/4 or 3/16" cut as large as would clear everything and machined to mimic the top of the intake. He then installed it between the Carb and intake. The problem went away.

I always ran pure dino 93 in my "former race car" and never had any problems except for an empty wallet. She spun a bearing and my new build is lower compression, higher flowing experiment.