I have been contemplating putting a set of Edelbrock aluminum heads on my 360. I was sharing my plans with some fellows I work with and one of the guys tried to deter me from buying them. I asked him why and he said back in the mid 90s when he was drag racing he had used a set of aluminum heads on his tube chassis car and had issues of the metal going soft. He said he discovered this, I believe when he removed the heads to repair a crack or perform a port job on them, I'm not sure why they were removed from the engine in the first place. Either way the machinist told him the metal had gone soft the heads were junk. This is the first I have ever heard of this, and although I am not a racer or pro. engine builder I have been reading magazines and working on cars for about the last 20 yrs. Is this something that was a problem back in the 90s and its now not an issue or is this something that could happen now. Most new cars are running aluminum heads so I have a hard time believing this is a current problem. Thoughts?