phenolic vs wood carb spacer

The wood spacers that I'm familiar with are not merely coated in a sealer, they are pressure treated. In the end they aren't much different from the phenolic spacers. They only differ in the type of volume filler. Phenolic resin w/o much filler, like in a ThermoQuad, wouldn't be very stable. Linen Micarta is very stable and is linen sheets laminated with phenolic resin. Also works good for low speed, high load bushings.

I've found that a heat shield, ala the fabled DZ-302 Z-28 part, made from 1/8" aluminum to work very well when moving the carb up due to a spacer means a hole in the hood. The one that I made was the length and width of the intake manifold.