Can you give me the low down on aluminum heads?

bjl95mustang

Founding Member
Jan 18, 2000
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Austin,TX
I'm getting a rebuilt sb this summer and I have been looking for heads. I have seen iron heads for around $250-400 and aluminum gt40y for $600 and edelbrock's for $700. How much better are the edelbrock heads that these other heads besieds the weight?
 
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I prefer aluminum in general, but aware that your effective compression ratio will drop with thew aluminum heads, unless you go with a slightly smaller combustion chamber. This happens because aluminum cools so much faster than irom. This is also why you can run 11:1 compression on the street with aluminum heads pretty easily.
Basically, be careful, you could actually lose some TQ&HP if you don't pick the right set-up.
 
ECU5.0 said:
aluminum heads are going to flow a lot more than iron heads period. but they are also more succeptable to warping if you overheat the motor

How do you come to this conclusion? Flowrate is a function of port size not material of construction. You can port an iron head just as big as an aluminum head. The surface smoothness of the material would have an effect on flow also but it seems to me that aluminum and cast iron would have about the same smoothness and if not you can always sand em down and polish them. What gives? :shrug:
 
warmdye said:
How do you come to this conclusion? Flowrate is a function of port size not material of construction. You can port an iron head just as big as an aluminum head. The surface smoothness of the material would have an effect on flow also but it seems to me that aluminum and cast iron would have about the same smoothness and if not you can always sand em down and polish them. What gives? :shrug:


You're right but I think he meant that most, if not all, of the better heads are aluminum. At least, I hope that what he meant.
 
I agree with QDRHRSE as to what I think ecu meant (boy, we are makin' stuff up). Notwithstanding the debate about the relative strengths and challenges, the simple fact is that the majority of folks who pursue aftermarket heads end up buying aluminum. So the market has shifted that way - you have many more choices in aluminum. At the end of the end of the day, I think all the strengths and challenges are a wash except for one. You simply can't knock 50 lbs. off the front of the car with cast iron heads.