Spacers keep the intake and t/b off of warmer parts of the engine…
When the car is heated up the block and anything connected to it get warm… one hot part heats up all the other parts…
A intake spacer raises the intake off of the lower manifold so theres no metal to metal contact helping reduce the amount of heat soak its picking up from the rest of the motor…
so that way when cooler air comes in, it stays cool and doesnt heat up before it even gets into the intake…
something like that im tired so it prolly sounds garbled