heads

[74roadrunner440]

which stock heads are the closed chambered heads and the ones that are the best ones that produce the best hp i know 516 heads are but what else are good heads?

 

[moparmarks]

1967 915 heads.

 

[RustyRatRod]

There are several casting numbers to choose from. I would have to say the best factory head is the 518 casting. Then the 915 followed by the 516. Although there are more casting numbers than that, I think those are the most popular three closed chamber castings, though there are more. What engine are you building? I am building a pretty hot stock stroke 383 and am using the 516 head. Although the port size is smaller than the 915, they will be plenty adequate for my engine and would be equally as adequate on a mildy moderate 440.....and I do plan on porting them. If you're talking about a 440, the 915 would be the better way to go.....BUT the purchase price can be prohibitive since they are considered "rare". If it were me, I would get a pair of 906s and have them gone through. You'll be money ahead.

 

[74roadrunner440]

i just built a mod 440 and used 516 heads that were porded n shaved w forged pisons and 509 cam and more power than i thought i could get i belive im pushing mid 5 to 600hp oh did i mention i put dual quads on also the hard part n still trying to mod a throttle bracket for the two carbs

 

[benno440]

http://www.moparmusclemagazine.com/techarticles/5115_cylinder_heads/viewall.html

for your throttle bracket "lokar make one for the 440 dual quads http://www.summitracing.com/parts/lok-tcb-40dq/overview/

 

[Meep-Meep]

For closed chamber design the 915 heads are the best to use and I don't even consider the Max Wedge heads as part of the discussion because they are too rare and expensive. Even if you buy the replacements from MoPar you might as well buy Edelbrocks and most likely have a better part.

Everything prior to the 915 is based on old technology and the difference is in the port shape (for non Max Wedge) rather than the size. The floor of the Max Wedge and 516 is flat but around the mid 60's Chrysler got together with Weslake (as in Harry Weslake of Gurney Weslake fame) and redesigned the big block heads. The result was a much better approach from the port to the valve pocket.

So my choice would be the 915 or the 906 (same port shape) and depending on where you need to target your compression you have the option of an open or closed chamber design. A zero deck piston with a 906 head will still provide quench for the purpose of swirling the fuel mixture in the chamber, but not as much as with the closed chamber. There is also a fine balance between quench distance and allowing the flame front access into that tight space to effectively burn all the fuel. It is said that Chrysler went with the open chamber design to help prevent detonation. I'm running pocket ported 915's on my 440.

 

[Moparsmitty]

Agree with everything Meep says. I'm running 906 heads on my 440 and i love em. Sure, I could probably squeeze a few extra horses out of a closed chamber head but with the 906s I can set my ignition timing where I want it, lean out the carb a little and not worry about detonation. I don't have to run racing gas or octane improvers either.