Just wondering if anyone has any info on these heads, aluminum Hemi heads. 2531110-M is the number on the heads. Thanks

They are basically a stock replacement style head but in aluminum, and in out of the box form flow just a little better than stock.

Designed for stock rockers, stock shafts, stock hold downs, stock hardware, etc etc

All that changes, big time, when the head is ported....as the performance of several members' cars will show.

Did you want historic perspective or exactly what kind of info?

I got it from both sides, man! Customer and Marketing.... but "don't get me started" is the first thought that comes to mind LOL.

Thanks for the info. I have a chance to by a set but just not sure. There lightly ported as well. Just not sure. I have a set of iron ones on my car now that we’re CNC ported and flow about 410cfm. The motor makes 825 with those heads, just wondering weather it’s worth it to buy those heads or just wait for stage 5 ones or edelbrock.

Didn't some of these have issues with dropping valve seats? Not sure, maybe I'm not remembering correctly.

I doubt there will ever be anymore Stage V's. And that's very bad.

Thanks! Good thread. So what do you think a full CNC porting job would do as for flow number’s on these heads?

I have those heads on my hemi. Makes somewhere in the 850 hp ballpark on motor only. They are CNC ported by MCH and max intake flow was 429.1 cfm if I recall correctly. I've been running them since 2006 w/ no real issues. I was worried after hearing about dropped seats from some people, but no issues w/ mine.

Valve seats falling out? What caused that with those heads?

I also have those heads on my Hemi with no problems. Those heads were made for weight loss which if I remember is around 50#s a head. When going from iron to aluminum heads you'll need to increase the compression because it'll lose compression due to heat loss.

Wow! I didn’t realize it was that much weight loss. How much compression does it loose? I’ve never heard that you’ll loose compression from aluminum heads. I’m at 13.08:1 right now.

I'm not for sure but I was told if both the heads were in stock form that they would add 1. Said it was a great trade off to lose 100#s.

I think you lose 30-35 lbs per side. And you can run 1 pt higher compression.

I guess I'm not sure if it really loses compression or it just loses power due to the heat loss???? But if you just change heads the engine will be a little down on power if they flow the same. Aluminum plus 1.


On the weight the original cast heads were a little over 60 but the mopar cast replacements were around 20#s heavier. The aluminum weigh a little over 30. So weight savings depends on which cast heads you have.

I have same head, new so I’ll clean them up like shown. Also have 12.5 pistons but they’ll be down .055 with a 7.045 billet rod and 4.5 crank. I think it will be fine for street

I also have a pair of the Mopar/Edelbrock heads on my Hemi also with no issues.

Thanks for the reply’s. I also was wondering what exactly has to be changed if anything if someone wanted to go with the stage 5 Millennium head? I know a guy that has both the stage 5 are pretty much complete with rockers and the Mopar head needs valves because one of the seats came out. Thanks

Please explain that there will never be anymore stage V,s? Did they go out of business?

He died. There isn't anybody there capable of carrying it on. It's for sale but no buyers have stepped up. This is a major hit to the 426 Hemi community like when Keith Black went down. And when Mopar Performance died. (I got on the Mopar website last month and there were 2 or 3 part numbers there for 426 Hemi's.) This is really bad.

I heard something about that but wasn’t sure if it was true. So is there special pistons that you’d have to use with the millennium heads? I’ve looked at a lot of old threads on here but couldn’t find much info on it. I just bought a set of 2 1/4 TTI headers and there for the stock cast head, now would they fit a stage 5 millennium head? How much needs to be changed to use them. I’m not even sure my pistons will work. Thanks for all the help.