Which head/combustion chamber is better for performance? Speed master aluminum LA or aftermarket magnum iron head?

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StreetSleeper

StreetSleeper

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If you already had engine blocks, even both heads to choose from to begin with, which head is better either for moderate street performance and which head is best for a max performance build?
 
StreetSleeper said:
If you already had engine blocks, even both heads to choose from to begin with, which head is better either for moderate street performance and which head is best for a max performance build?
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None of those heads are for a max performance build.

You need to define your terms differently.
 
Newbomb Turk said:
None of those heads are for a max performance build.

You need to define your terms differently.
Click to expand...


There are some pretty nice magnum heads out there but the trouble is they came on Mopar crate engines or other sources and are no longer available. A friend has a set on his 408 based engine that runs 10.70’s. (2.05 valve). Edelbrock, Speedmaster, ProMax, TrickFlow, etc can be made to go a lot faster. But all require extra work. As did the magnum heads on my friends build. But like it says above more info is needed
 
pittsburghracer said:
There are some pretty nice magnum heads out there but the trouble is they came on Mopar crate engines or other sources and are no longer available.
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Which head is that? Most of the crate engines I’m aware of used either;

Cast iron magnum head
Cast iron magnum R/T head
Aluminum edlebrock magnum head
 
TT5.9mag said:
Which head is that? Most of the crate engines I’m aware of used either;

Cast iron magnum head
Cast iron magnum R/T head
Aluminum edlebrock magnum head
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He’s told me probably 4 times and all I know is it was a better magnum head that was on factory crate engines and is no longer available. The short side excited my fingers. Kinda like a W2 only different.
 
pittsburghracer said:
He’s told me probably 4 times and all I know is it was a better magnum head that was on factory crate engines and is no longer available. The short side excited my fingers. Kinda like a W2 only different.
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Were those actually magnum heads? I had two sets of those with the improved exhaust port but I didn’t think they were magnums.
 
Other than replacement magnum heads isn't the only aftermarket magnum performance head done by Edelbrock ?
 
StreetSleeper said:
If you already had engine blocks, even both heads to choose from to begin with, which head is better either for moderate street performance and which head is best for a max performance build?
Click to expand...
Might be a good idea to tell us which pistons you plan to use.
 
For all out, one of the newer aluminum castings. The best between the OEM castings? Shaft mounted rockers or stud mounted. Shaft is more stable. Closed or open chambers? Pretty sure there are available pistons that can help the open chamber. In the end, I wouldn’t sink a dime into a cast iron head if I wasn’t required to.
 
273 said:
Other than replacement magnum heads isn't the only aftermarket magnum performance head done by Edelbrock ?
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Edelbrock Aluminum Magnum and:
Mopar did an Iron ‘R/T’ head
Maybe the Engine quest head (from ?Auatralia??) was also better than the Chinese magnum repo head as far as I remember from the forums-something about a water jacket plug on the side of the good heads..??
 
furrystump said:
For all out, one of the newer aluminum castings. The best between the OEM castings? Shaft mounted rockers or stud mounted. Shaft is more stable. Closed or open chambers? Pretty sure there are available pistons that can help the open chamber. In the end, I wouldn’t sink a dime into a cast iron head if I wasn’t required to.
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Both of the mentioned heads are closed chambers, each with either shaft or stud mounted lifters-they are price comparable entry level when replacing heads on a SBM.
 
StreetSleeper said:
Edelbrock Aluminum Magnum and:
Mopar did an Iron ‘R/T’ head
Maybe the Engine quest head (from ?Auatralia??) was also better than the Chinese magnum repo head as far as I remember from the forums-something about a water jacket plug on the side of the good heads..??
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I meant available new.
 
Just the Chinese repo with a few engine quest heads and an occasional RT set popping up for a quick second at the different marketplaces either under $2K usually sir.
 
StreetSleeper said:
Either KB-107 or Speed Pro H116cp

Cam would be smaller than comp cams XE 268 for the street build
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I've used both those pistons and I would recommend the Speed Pro. No special ring gap requirements.
 
pittsburghracer said:
He’s told me probably 4 times and all I know is it was a better magnum head that was on factory crate engines and is no longer available. The short side excited my fingers. Kinda like a W2 only different.
Click to expand...
Thanks, that was definitely the cast iron magnum R/T. They were a magnum style head with W2 influence. @Brian Hafliger at IMM is currently evaluating a set for me now. I’ll post what he finds.
 
pittsburghracer said:
There are some pretty nice magnum heads out there but the trouble is they came on Mopar crate engines or other sources and are no longer available. A friend has a set on his 408 based engine that runs 10.70’s. (2.05 valve). Edelbrock, Speedmaster, ProMax, TrickFlow, etc can be made to go a lot faster. But all require extra work. As did the magnum heads on my friends build. But like it says above more info is needed
Click to expand...
Mentioned were Edelbroor Performer, TrickFlow, Speedmaster and ProMax heads. What about the 1970 and 71 stock 340 heads with the large 2.02 valves? Are any of those aftermarket heads better/worse? The literatures says "increased performance". Performance doesn't necessarily effect gas mileage. What's the story?
 
rebelcaptain said:
Mentioned were Edelbroor Performer, TrickFlow, Speedmaster and ProMax heads. What about the 1970 and 71 stock 340 heads with the large 2.02 valves? Are any of those aftermarket heads better/worse? The literatures says "increased performance". Performance doesn't necessarily effect gas mileage. What's the story?
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Don’t ask me about gas mileage. It’s a subject I never cared about or studied. As far as going quick yes an X or J head can be made to go fast, real fast. My street car ran 11.82 with them back in the 1970’s and that was with junk parts. A friend has a set running 9’s with small valves but it’s a drag only car.
 
Out of the box Speedmasters are close to equal to X's or J's. Did I read that somewhere or am I completely wrong?
 
toolmanmike said:
Out of the box Speedmasters are close to equal to X's or J's. Did I read that somewhere or am I completely wrong?
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Out of the box Speedmaster heads are in the 250cfm area. I’m betting a J or X head can be made to flow better than that but be prepared to pay a handsome price. I could do a set for free (or close to free) and I’m not even interested.
 
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