OUTLAW525

I have a 2002 aluminum headed 5.3 out of a truck and an all iron 6.0l out of an 2003 truck, both have pistion slap and will need to be bored out (got the 5.3 with all the fixens for $200 core charge) I want to use the 6.0 blockand bore it out and put larger pistions in it. Question is, will the alluminum 5.3 heads be better than the iron 6.0 heads. I want to lower the weight of the engine package. Would it be better to sell the heads or to keep the 5.3 heads and have tham ported.