iv had my monte for about 2 weeks and it rained 1 day and i went and checked the car for leaks and it was leaking passenger side under the dash. today i was workin on the car and it decided to downpour and it was leaking again so i found the leak and started pullin all the AC and heat stuff under the hood and come to find out the whole box is busted up/melted. what im wanting to do is put only heat in the car, but im having trouble finding a heat only box for the car. anyone have any ideas on what i could do to put only heat in or find a box that i can put the fan/heater core in?

 

under the dash most likly on the passenger side