Modding the Heater

Unfortunately, the passenger heater was not exempt from the modifications so here's how I modified the heater to work around the custom mods to the engine compartment's passenger air intake. In a stock engine compartment, the straight 6 is quite narrow. There's room to run fresh air intake tubes from the rad support through the engine compartment to the firewall.

Room to run fresh air intake tubes in stock engine compartment

Throw in a 400 cid SBC, battery mounted on the firewall and power brake master cylinder and the room disappears!

With the mods that I've done, there's no room for the stock fresh air intake tubes. Another solution was required. In my case, I mounted fender scoops from a 54 Cadillac air conditioner. Normally, fresh air passes through the firewall to reach the heater core with the heater core is mounted directly against the passenger side firewall. I had welded shut the 4" diameter opening because the firewall mounted battery was in the way.

Soup cans soldered on to the heater box for fresh air intakes.

I used soup cans to form new air intakes that will be connected by flexible heater hoses to the fender air scoops. The flexible hoses run from both the driver's side and passenger side kick panels. It works quite well!

Heater Fan Motor

Just a quick note on the heater fan motor. It is a 6V motor and works great without any modifications at 12V. GM did a great job of over engineering it as it can run all day at 12V without a problem!

Heater Core

I had two heater boxes and when I checked, both heater cores were in great shape. I flushed them out using a garden hose then pressure tested them on the running engine. No leaks and they both looked like new. The one issue that I did have was the heater temperature controller was rotten and leaked badly but that's for another page..

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Copyright January 2012 Eugene Blanchard