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Discussion Starter · #1 ·
Is it worth the time and money switching from a brodix11x head that flows around [email protected] to a set of raised runner heads, is it going to improve cosiderably btw its a sbc 434:confused:
 

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Better to go with 18's or 15's, the money for AFR RR's or All-Pro's along with shaft rockers would be better served going to a rolled head.
 

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The only thing to consider is if you might end up running in any classes that require a stock valve angle head.... if you can't forsee anything like that in the near future then it's time to get away from 23 degree land.
 

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I have been working on a new head to fill the gaps with the larger small blocks and higher revving small inch motors. It is a 235 cc 23* head that uses all std valve train. It goes 333 cfm @ .700" and is cnc ported in house. It is a really nice head if you are looking for a bolt on 23* package. I am building a 406 this week to put a set on to see what we can get out of them. I would think that they should make 680 to 700 on a single 4 with the cam. We will see in a day or two.;)
 

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Keep me in the info loop. I am interested in that as to 11.25cr pump gas 434sbc. Thanks.
I have been working on a new head to fill the gaps with the larger small blocks and higher revving small inch motors. It is a 235 cc 23* head that uses all std valve train. It goes 333 cfm @ .700" and is cnc ported in house. It is a really nice head if you are looking for a bolt on 23* package. I am building a 406 this week to put a set on to see what we can get out of them. I would think that they should make 680 to 700 on a single 4 with the cam. We will see in a day or two.;)
 

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Aside from a 245RR All Pro, the normal thing to expect for a gain from, say, a 101 Bowtie or an 867 Pontiac vs. low port heads is 30 HP if both are prepared by a competent source.

I also agree its better to abandon ship on all that and move on to a more current cylinder head package. The only thing you accomplish with a 23° setup is "maybe" lower upfront cost.

Consider the fact that an 18°/15° or similar generally does NOT require:

- Domed piston (heavier & reduces fatigue life in the rods)

- Excessive spark advance (usually translates to a wider tuning window-less likely to get hurt)

- Deep valve pockets (23° pistons HAVE TO be taller to facilitate rod top end to piston underside clearance)

- Excessive spring pocket cutting or raised height valve locks (casting & valve integrity)

There are way too many good reasons to start off with something other than a 23° head for any real racing engine, and you (generally) will always make a SIGNIFICANT amount more power with the more current designs.
 

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If you do leave the 23 degree head arena, are you then out of the pump gas arena and into race gas because of higher CR?
 

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Discussion Starter · #11 ·
thanks for the response, I will also mention that I have a 421 18* 363 gm headed sbc that is pump gas but I was told it will not work because of the low comp, is this true because I was very disappointed to hear this. thats why I wanted to go with a rr head on the 434.
 

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Currently building a 427,11.0 to 1,tall deck,pump gas,18* street motor.......

Should do 625-650 on motor and 400 more on nos and race gas......

Stock suspention 67 chevelle............

It`ll work.......
 

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I am in the same boat. I have a set of 11X that are NOT raised port, just spreadport. I don't think there is too much more to gain with them with further porting. On one flow bench they were 320 through the intake, on another they were 308. I believe the second more, but it really doesn't matter. There isn't another 100 hp to be found in them.

What heads would be worth looking at? Not a heads-up car, bracket motor only. Reliability and low maintenance are the only things that matter to me. New pistons? Can I actually get above 14:1 with something close to a flat-top? Decent enough cast intakes available for these types of heads? Just looking at options for next year............
 

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Everyone here has offered really good advice, .. unless you
have class rules to meet, .. drop the 23* stuff and jump to
18* or 15*.

There's some great deals on 18* stuff and a hand full of very
good porters for them, .. and you'll be happy you did.

Curtis
 

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Curtis,

I have used Al before, and i`m really happy with the results.........

He was VERY interested in doing this particular project, so i gave him the green light...can`t wait to see the results......


Most people i talked with were leery of doing this motor with 11.0 to 1 comp..

They said it needed more........
 

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Currently building a 427,11.0 to 1,tall deck,pump gas,18* street motor.......

Should do 625-650 on motor and 400 more on nos and race gas......

Stock suspention 67 chevelle............

It`ll work.......
I'll be curious to see how this turns out for you.:cool: A fella on the chevelle board did one of these 6-7 years ago. He used the Dart 18's. It made ~650 with efi.
 
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