[Tom]

Originally Posted by SmirchIs#1

As stated earlier in this post,the aluminum heads dissapate heat faster than cast iron,so you can run a little more compression.Keep in mind that is at a trade off of making less power.If an aluminum head is compared to a cast iron head And they are similar in design,the cast head makes more power hands down.The heat retention of the cast head more thoroughly atomizes the incoming fuel charge,thus making more power. No I am not making a comparison between Stock cast iron & more exotic aluminum heads.

You're contradicting yourself. The added heat retention of the iron head is why you have to run lower compression vs the aluminum to avoid detonation. By upping the compression on the aluminum head the same overall heat values are maintained and power goes up. If iron heads were the way to go then they would run them OEM. They haven't since what, 2000 in the vans?