Jay, that doesn't say too much. What's it used for, type of car, trans, intended usage. All these need to be addressed. Out of the box, never seen or heard of anyone using out of the box stuff. But if your not going to port these, and rules allow, would have to say Profilier 12 deg. are the way. But there are so many out there that you need to narrow the margin. EPD and CFM also sell heads as a package. But allot of what I've been seeing and told, 18 Deg. Pontiacs "427" casting are better on Nitrous than most of the others, little more forgiving and wider power range. The "Olds" will make more peak power, but harder to tune. But if your still wanting to run Big Chiefs you might want to refine your question a little more.
PM me some info and will see if i can help. John 8)