Extreme heat in 1974 Big Block

[Tom L.]

Re: Extreme heat in 1974 Big Block

As mentioned above, if it's an A/C car check the seal around the heater core tubes. Over time I don't think the seal was replaced with the core, it's a pain to get at. That seal made a HUGE difference but the big blocks are real hot, even in cool weather.

[Lyndon S.]

Re: Extreme heat in 1974 Big Block

Make sure the heater control valve is working. I live in southeast Texas, and I have a 1971 LS-5 so I know where you are coming from. The main thing I did and it got rid off a lot heat coming in was to replace the missing tunnel shield that goes on the bell housing. You would not believe the difference that one small piece of foam made in keeping heat out of the cabin!

Lyndon

[Jephrey S.]

Re: Extreme heat in 1974 Big Block

I had a similar problem in my 70. All of the previous suggestions are good and I tried most of them. My problem ended up being the exhaust splice on the driver's side adjacent to the tranny had worked slightly loose. I could see soot deposits at the seam. The shifter (manual) would get so hot that you could not hold your hand on it. I replaced the pipes and the heat problem went away. You said that you have wrapped the exhausts, so this may not be your problem but every data point helps. Of course, it is not exactly cool with everything working properly.