Heater box help

[Malibu455]

Hi All,

I am putting a 455 olds in my Malibu. It does not have stock heads and the heater box is in the way. I cut a hole in it, but I need more room. I am attaching some photos. I need help. My box has A/c. Is a heater only box smaller? Any help would be great. you guys are the Best. sorry about how the photos attached.

 

[85ss/85gn]

It is small may still have issues

 

[Malibu455]

Hi Thanks for the photo. on the right side (engine side) it looks like it is flat for a couple of inches. Its hard to tell in the photo. If it is can you tell me how many inches before the it starts to rise? can you measure it to the center of the hole so I would have a reference? Maybe one measurement from the bottom hole and then one from the hole above it? Where do the heater hoses go in? Thanks

 

[85ss/85gn]

Heater hoses are on the other side of the blower motor.