I dunno how much truth there is to that. My aluminum heads make me hell of allot more power that my stock iron heads ever did. As far as durability goes, I imagine that I'd have a much tougher time damaging my cast heads with saaaaaay a bullet from a gun than I would my aluminums. A,uminum heads are all the rage... they're light, easy to machine, and mate well on blocks that are less than perfect in a lot of cases. The only recommendation of cast over aluminum that I personally have read, was from a supercharger manufacturer that said that cast heads absorb and disipate hear better than aluminum. I think that that's debatable as well. Absorb... maybe... I find it hard to believe that cast iron would disipate heat more readily than aluminum though.