Maybe not zero, but very low indeed. I would disagree about an insulator not making a difference. Phenolic spacers have been used to good effect for a long time. It's not the temp of the incoming fuel, it's the manifold heat boiling the fuel in the bowl that's the problem. Phenolic, or any other insulating material, will help this condition.
'69 1/2T stepside, Sea Foam Green, 250 L6 w/ 3 on the tree, not an option on it, in the family since new.
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