I have been looking at aluminum heads for my big block 440 for a long time now. I was dead set on a pair of 440Source Stealths then I thought it was going to be the Edelbrock E Street 5090 75cc heads, but as of now I'm giving the MP P5153524 "452's" a serious look. I understand these are basically Eddy RPM's with straight plug holes. Before I pull the trigger on a set I would like to get some input from those of you that have a set of these aluminum 452's on their engines.