I'm building some 550hp motors, Naturally aspirated and am undecided between which heads to buy. The pro's for the alluminum I am hearing is that I can make more power. And the cons I have heard is price difference and upkeep. Does anyone have some good info to assist me in my purchase?
Let me know,
Bruce

The other I day had to pick up and move an old cast iron head in my garage and that reminded me how heavy these are. If you go with aluminum you will save about 60 lbs. per motor, not to mention your back when you have to move these things around. Saying aluminum heads produce more power is a good topic to debate. If the heads are of the exact same design, the iron may make more power because they don't cool as quickly as aluminum. If you plan on using aluminum heads you can bump your compression by 1/2 to 3/4 point. This will make up for some of the heat loss due to the faster cooling properties of the aluminum. In most cases modern aluminum heads flow better than the old iron heads they are replacing, therefore they make more power. Also aluminum machines easier so porting is easily done. My opinion is to polish your combustion chambers, run 10:1 compression with aluminum heads and the appropriate cam and you'll make some good detonation free HP on 92 octane gas. You do need to be careful if boating in salt water when using aluminum. Good luck!

Wette, thanks for the reply, although I hope they will not be laying aroung my garage to often I will be doing 1/2 fresh 1/2 salt water boating. I do take very good care of my equipment and don't think it will be too hard to make the alluminum last. And you gave me a lot of good points for both. I guess I just can not justify the extra $1000 for the alluminum. In my case its for twins so, a $2000 upgrade. Leaning towards iron heads at the moment.

Ask Edelbrock if their marine Aluminum heads will stand up to the salt and letus all know.

I have alum. Elebrock 6055 performer heads on 454 mags. It has fresh water cooling now, but it didn't always. Heads have really only been on since FWC was installed. Intake is original alum though, and is pretty well shot after 13 years of service, some salt, but well flushed.
I like the alum other than these heads are hard to keep torqued properly. I guess the dissimilar metals make the expansion and contraction significant enough to loosen head bolts.

My .02,

BT