I live at 9k in Colorado and it does get quite cold sometimes, like -35 overnight or 4 daytime high, but it is generally low humidity. I am putting an edelbrock streetmaster on my fe 390 with a qjet that Cliff has helped me dial in. I am hearing that if I don't block the exhaust crossover the exhaust will severly corrode the aluminum and ruin the intake. I would like the heat in the intake for winter, summer heat can be handled easily enough. Did GM make a qjet spacer with coolant flow to warm the carburetor, I know at least Ford did. Does someone make an electric carb warmer baseplate? I do have a coolant heater on the truck that warms the engine and makes very cold day starting smooth. That may be enough, I have a qjet on my dodge 318 with iron intake and open crossover which starts and runs fine after warm up on those silly cold days.