With a tunnel ram with 2 750 dp carbs on gas with no hood in a 67 Dodge R/T,the wind blowing across them would start to pull gas up out of the vent tubes. Do you have the toilets sealded to your scoop with hood on. I tried that also on my R/T and it would not run,sealed it to the scoop run fine. Sometimes the little simple stuff will cause problems,they do for me