heat shield for my slant six!! HELP

57dodged100 said

"This product is not recommended for the use on: 1. Intakes with heat crossovers and EGR values in the intake. 2. Straight 4-6-8 cylinder motors where the exhaust and intake overlap. 3. Some castiron intakes have had an issue also. REASON: The polycore is an excellent insulation but it cannot take the extreme heat that the exhaust creates. This causes it to get soft or melt."

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This is interesting in that they appear to be saying that this product is useless on most of the vehicles sold in the United States since 1971.

1. EGR systems came into common use in the US in 1972. All of them have vents under the carburetor which allow exhaust gasses to pass into the intake for re-consumption. Almost by definition, an EGR valve is in the intake on a carbureted engine. Technically, a heat crossover is only found on a V-type engine allowing exhaust gas to warm the carburetor.
2. I have not seen an inline, ohv, pushrod motor that didn't have at least two ports siamesed. If they are talking about valve overlap, then one has to go back to the powered buckboard days to find a gasoline engine without valve overlap.
3. This seems to be the only leg they have to stand on. Most carbureted cars built in the US since WWII have had cast iron intake manifolds.

Ask Dan to check me out on this. The throttle bore on the 1920 is 1 11/16, where the hole in the plate is 3/4. This means that the hole in the plate is 1/16 too large. IMO, that's not a big deal, but it can be if the bottom of the carburetor isn't fairly flat.