body drop w/ a/c & heat

i have a 89 and i am getting ready to cut my cab this weekend and i am wanting to know if it is possible to cut around the heater core on the transmission hump so i can keep it on the truck? and if anyone has done a body drop and kept there a/c on the truck, it is no big deal if i have to remove the a/c, it but it would be nice to have..