440 source heads vs Edelbrook rpm heads

[Chryco Psycho]

Most Alum heads use the closed chamber design for quench /anti detonation , the 906 open chamber is actually a smog headusing the Best head for your combo is a difficult thing to determine , a 500" engine with smaller heads can make some wicked power #s but you will see them all in the lower RPM range which is not nessisarily a bad thing in a street combo ,while big heads on a small " engine is definatly more of a high RPM race thing . Indy used to advertise 100 hp bolt on with their 440-1 heads but the reality was most engines barely gained at all as the heads wer too big unless a lot of other parts or more CI was part of the pkg 

[bb71challenger]

You have had some experience with the Stealth heads Neil, are they something you could just bolt on and not worry about or do they need extensive mill work to get them right? When the time comes I want to be able to put a set on out of the box and get good results. It has always bugged me that you spend a ton of money for a set of good heads and then have to spend a ton more to get them ported/trued just to bolt them on.

[nivvy]

Well i just say this... here is my 500 before I slapped it in  with ported 2.14*1.81 906 heads... and of coursee other changes along the way 

this setup in the pic just fried the tires off ... easilly

You can find re worked heads already doneat a good deal these days....

[73EStroker]

bb71 and Grancoupe

I hear what you say. But my heads are EZs from Indy with the 295CFM ports. And the nice thing here is they take all stock hardware - absolutely no after work had to be done. Paid my money and bolted them in. These heads would work on a 383 but yes it would need a decent cam and a good velocity manifold to keep the driveability there down low. I run my heads on a 451 stroked 400 low deck and seeing as it is a 4 speed I run a Lunati 286 duration @50 0.586 lift cam with the Holley SD manifold and a 950 Proform carb. So the point here is that I have a combo that is a mix and match for driveability but it does not stumble at all straight off idle. I want to run this thing up to 7000 and it was built this way. So all of my homework must have paid off (ask CP for his opinion on this engine). Now time will tell when this thing is on the street and we really see what happens. But if I were rally_73 I would contact Eric at Muscle Motors and ask him if these heads would work for him. I do not believe they would sell him something knowing it will not work.

[nivvy]

bb71 and Grancoupe
I run a Lunati 286 duration @50 0.586 lift cam

286 at .50

[moper]

Any cnc head package has had the valve job corrected. MM does this, as do Porter Racing Heads, Modern Cylinder Head, and Indy. Honestly, buying Stealths is not spending big coin on a set of heads. Its unfortunate, but you have to pay to play. I know some very fast cars with mild heads, but good isnt cheap. Mild good is still decent coin even for iron. This is why a set of cnc RPM heads is $2800 vs $1400. And why even with stock ports, RPMs I install go for $1700 ready to install, plus any changes in springs/retainers/locks. You can bolt any set on, but at minimum, you are not getting the maximum power of life, at the maximum you may end up with hanging valves or valve and seat sealing issues.

[Chryco Psycho]

255 or256 * @ .050

I haven`t built the stealth head stroker yet ,but my advice is no head is a bolt on out of the box , even 73E heads were gone through by Muscle motors before shipping

[nivvy]

I do think the only way to go with steatlhs is that Jeff at modern cnc's them and corrects stuff.... I guess 440source n Jeff have a deal now.... but thats the way to go for those heads 

[71chally416]

The issue becomes do you really want to put that much $$$ into stock clone heads that have better chambers but the same limitation with the short valves, or use better castings with more potential for a big motor?
For a 383 it makes sense, but for a 500 cube motor I wouldn't. 

[nivvy]

I believe my iron 906's went 285ish cfm alot more than stock stealths.... but what you would need to make the stealth head be functional with 500 cid the cost would be alot more with machining costs needed also...

I would never take and old set of irons and pay to have them fully worked unless it was a set of vintage max wedge heads... 

[Chryco Psycho]

The only advantage to iron heads is the heat retension in the cylinders ,this makes a Big difference in power used vs lost to the cooling system & underhood heat as Alum creates a lot more heat in the engine compartment
Indy used to offer an Iron version of the SR head ,not sure if it is still available though , last time I checked I couldn`t get a set

[73EStroker]

Sorry - CP is right 255@0.050". Musta been  something when I last posted. All MM did was ensure that the valve lift would be good for 0.600". I bought Eagle rods, Ross pistons and the heads from them so they matched them up to each other for me to ensure a trouble free engine build. They even machined dishes into the pistons to keep the CR at 10.25 with an 0.040 Cometic gasket.

[bb71challenger]

Hey CP, I have a set of 516 iron heads, are they worth going through and porting? I know I am not supposed to use the same porting templates from Mopar Performance that I used on my 906's so what do you suggest? I dont really want something crazy if I dont need it. Any way to open up the 516 ports to max wedge size? Is the meat there?

[Chryco Psycho]

Well most people will tell you you are wasting your $$ & the 516 heads are crap ...But I won`t , for a street head they are good , open the exhaust up for the bigger 1.81 valves & install hard seats , you have the advantage of the closed chamber which will help kill detonation & they will make power , I did  a set for my Duster & it ran mid 11s weighing in at 3440 lbs with me in the car , it was definatly over 525 HP & ran great , it would have gone faster with better heads for sure but this was back in the mid 80s & not a whole lot of heads were available & they were out of my budget for sure
 I ported them using the Mopar templates & did them before I learned & a lot more of the tricks I use today , they will not go out to Max wedge size but you can get them opened up not that size is everything either , velocity makes a big difference as well , shaping around the guide is huge , the templates offer not assistance in that area but you can add swirl & clean up turbulence around the guide , don`t cut into the floor of the port , if anyhting weld some more iron in there lol , I always add some width int he pushrod area but don`t get crazy & break through the wall , this creates a venturi & speeds up air flow behind the valve , I do widen it more at the top where most of the flow is though , & port match the opening , on the exhaust side & widen the port extensively & raise it approx 1/8 ", agin don`t cut into the floor , more floor height is a good thing , I don`t even polish the floors , on the intake side it will help trap raw / unevaporated fuel & on the exhaust side the turbulence will drive the flow higher 
 the bottom line is you will spend close to $1000 to do a set of 516 heads , unless you do the porting yourself , I Charge $500 to do them so that cuts the cost in 1/2 , to buy Stealths you will spend less but you lose 1 point of compression & may have to address that issue to maximise power & you may need to have the heads checked & fixed  for machining quality & you will have to buy better retainers & locks & probably better springs as well so even that may not work out very cheap & any other head is more $$ yet while the 516s will be adequate for a lot of street builds & you say you don`t need crazy , would mid 11s potential be enough ??

[bb71challenger]

mid elevens would put a smile on my face that would never leave     I wish I had picked the 516's up before I had my 906's worked. Maybe on down the line I will contact you if you take on projects that are shipped. I would love a nice stock looking set of closed chamber heads. I am the type of guy that paints the whole engine, anything to make it look as much like stock as possible. I would rather walk softly and carry a big stick if you know what I mean. If I had the 516's done I could use the valvetrain parts I am using on my 906's right? Maybe if I am lucky I could even use the Smith Bros. pushrods. Thanks for the reply Neil, I am glad I spent the 60 bucks for the 516's now.