Could I install the gaskety without cutting out the square that the coolant goes through? How much of a difference does the coolant make? I always thought the majority of the heat came from the physical heat transfer between the head and the manifold.

I remember reading an extensive post about this before but it seems to have vanished.


So I understand that heater function will be gone if i leave the square on..but will I lose AC function as well? and also is there a way to bypass the coolant so heat would still function?