Cast or Alum.heads for racing.

I,d like to run low 11,s and I,d be happy,high 10,s would be nice but also cost more?I,m going to Moparfest on Aug 15-16 and hope to find a deal on some heads.AARCuda what should I look for(damaged,cracked)on an Aluminum head?This is if I run across a pair of used ones,cause I seen a few pairs last year.If I can pick some up for 1/2 price used,that would be nice to have extra money for a bigger cam and better intake.I don,t like my Torker II,and will be selling asap.