Smokey said:The head to head crossover through the intake ?
YES lots of people, especially those who do not really need carb heat for cold weather driveability, block those passages.
Moparman440 said:I have run vehicles both ways, and I wouldn't do it (block the exhaust heat crossover) on a daily driver unless I was highly concerned about getting every last bit of horsepower out of it. They run better when cold with the crossover un-blocked. You may lose a few horsepower on the top end when it is warmed up, but for a daily driver or a stock truck, I would leave it flowing.