FYI Choosing Heads: Aluminum vs Iron

[6 packin]

This web page is from Hughes engines a respectable Mopar engine specialists! There is some good points to mention here when look for a set of heads like Edelbrock or other aftermarket heads!

Hope this helps a little!

http://www.hughesengines.com/www/hug..._head_tech.asp

[Magnum440]

I think for the complete novice that is a fairly accurate explaination of "stock replacement" vs "bolt on". It is simplified, but thats OK and I wish I could have read that 4 years ago.

BUT, in reality, how many buy aluminum heads to just "replace" their stock ones? I've always thought that was a little silly. Even if you have a set of ported iron heads are you not going to have "non-stock" parts in them like roller rockers, moly push rods, ss valves,etc? "Bolt On" is sort of a mis-nomer,as well, since most hi-po race heads use "studs" as fasteners.

And Hughes did'nt even mention raised exhaust ports specificly. Often these heads require custom made headers. The one MP aluminum mentioned--"383/440 Aluminum Head" I've NEVER heard of anyone buying until yesterday. Mopar Muscle evidently is testing a set. But most people never heard of them! Even though they have been listed in MPs catalog for several years now.

All in all, I appreciate you posting this link. There IS alot of confusion about aluminum heads. And I would advise anybody looking to buy some to get Chuck Senatore's book "BIG-BLOCK" Mopar Performance available from the Muscle Motors web site www.musclemotorsracing.com

And as Hughes said, have a plan, and compare results/experiences of others who've run the combo.

[ehostler]

I also think that Hughes is a little biased on this, as they don't make anywhere near the profit on the EB heads, as they do re-working iron heads.

I've read about several people (some here) that have seen good ¼ mile improvements, with the EB heads, over mildly worked 906 heads. Most of these people were using stock compression with aftermarket cams.

So, I must agree, if you want the FACTs, then you need to actually talk to people that have done this to their cars. Not the biased views of a machine shop or a magazine

[Doug Wilson]

I think that is a really good point. When was the last time you saw a mag say something like "...except for the poor quality control, this might be a nice part" or "After testing this XYZ(big brand name) part, we have found it to not only cost you power, but it's made in Red China, and is pretty much junk."?? The mags know who is paying their bills, and it isn't the subscriber, it's the advertiser.

As far as aluminum heads go, I put unmodified Edelbrocks on the 340 and like them fine. The great thing about aluminum heads is that you can go up 1 or 2 points in compression ratio on pump gas. If you look at all the old really fast cars, as well as the new ones, lots of horsepower is made with high compression. This, to me, is where the aluminum heads shine (pun). The 340 is running 10.5:1 on 87 octane, with a mild (low overlap) cam and an aggressive timing curve.

The engine was built for the car - a '66 Barracuda - so I can't make a direct comparison to stock or ported iron heads, but I researched it a lot and I don't believe you can match the performance gains for the same money - $1150 - on a street car.