anyone ever flow test 383 A body manifolds say vs 383-440 hp manifolds

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Jeremiah said:
No, I have not recieved any build advice from Andy directly. All of my parts come from AR dealers. Does that answer your question?
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No it doesn’t and it’s OK. I’m backing out & thank you very much for your time, sorry to waste yours.
Good day.
 
66fs said:
I don't think the manifolds were the only difference between an A Body and B Body 383.
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What do you think made the difference other than restrictive exhaust?
 
66fs said:
The smaller cam, combined with the more restricted exhaust.
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Had the same cam as the 383 4bbl in all models except the roadrunner package.
I think the restrictive exhaust was a major factor.
 
Jeremiah said:
No, I have not recieved any build advice from Andy directly. All of my parts come from AR dealers. Does that answer your question?
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You grudge racers are so secretive. lol
We want to know all the parts you are using and from who. lol
 
How do we really know if there an hp difference between A and B body 383's factory gross hp number are unreliable, could of rated them different for sales/insurance/competition etc.. I guess the 4 gear 340 cam makes no more hp than the regular 340 since there rated the same hp or 340 carter avs vs thermoquad.

I'm sure there's a slight difference between manifolds but since we have no dyno comparison we won't know, but judging from what dyno shootout of other manifolds and shorty headers and even long tube headers over the years I would think probably 1-5 hp and 10 hp max.
 
273 said:
How do we really know if there an hp difference between A and B body 383's factory gross hp number are unreliable, could of rated them different for sales/insurance/competition etc.. I guess the 4 gear 340 cam makes no more hp than the regular 340 since there rated the same hp or 340 carter avs vs thermoquad.

I'm sure there's a slight difference between manifolds but since we have no dyno comparison we won't know, but judging from what dyno shootout of other manifolds and shorty headers and even long tube headers over the years I would think probably 1-5 hp and 10 hp max.
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I'll wait for Jeremiah to do his testing. I'm sure he'll provide honest results, although a modified engine is being used. I'm looking forward to his tests later this year.
I still think the restrictive manifolds and smaller head pipe on the a-body costs horsepower on the factory big block.
 
Jeremiah said:
If you re read your own posts there is no question mark to be found at the end of any sentence. I am so confused lol.
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OK, no problem, thank you, move along, have a great day, thanks for coming, see ya, bye bye now, adiós, hasta la vista, have a great day, enjoy, bye bye now!
 
I plan on testing that theory later this summer with my 499". I'd like to do a modified c, b hp and bb a body on the engine dyno.
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Looking forward to it.
And the headers too:thumbsup:
 
As bad as the ex manifolds are, on what I’ll call the “higher effort”(but def not max effort) FAST legal type builds, the factory iron square flange intakes are also quite poor for making big hp.

I dynoed a nice little 511” low deck FAST build one day, and a 499” 6bbl build the next day.
Both were very close to 12:1CR.
Same exhaust manifolds and 2.5” pipes used for both.
Same solid roller cam in both, 906’s on both, and the 511 heads were a few cfm better.

The 6bbl combo made about 65hp more than the 4bbl combo.

At a FAST event, the 511 went 11.58@117 at 3670lbs, thru the ex manifolds and 2.5” exhaust system, on G70-14 repro redline bias plies.
 
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DO THE 383 A BODY MANIFOLDS FLOW SIMILAR NUMBERS [SIDE TO SIDE]? OR IS THE DR SIDE MCH WORSE THAN PASS SIDE?
 
I would think it has to be due to that huge flattened kink as it goes around the steering column. :eek: No way to be absolutely sure without a flow test. And then, on every particular combo, it would have to be comparison-tested on the dyno vs. a non-kinky manifold.
 
My understanding is that the difference between log manifolds and B-body HP manifolds is about 5hp. The other difference between a 350hp 440 and 375hp is the cam and carburetor. I don't know about the cam specs in the 1967 A-body 383. The claim from the factory was that the 280hp was due to the manifolds (considering the above I find that very hard to believe). 1968 is even more interesting. Reports are that NO 340 came in under 320hp in the dyno room, but could have that and rate the 383 at 300 like they did that year. Same reason they couldn't keep the 1967 280hp rating. 1960s horsepower ratings were based more on marketing and insurance rates than they were from reality. It's doubtful that there is much difference in HP between the logs and A-body manifolds.
 
I would love to see actual flow numbers on the stock A Body manifolds and B Body manifolds. I thought someone would have already done this.
 
davescuda said:
I would love to see actual flow numbers on the stock A Body manifolds and B Body manifolds. I thought someone would have already done this.
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Based on my personal experience with "absolutely" no real evidence, Short of strip time. The A-body manifolds flow near as well in 69 as the SB an RR B-Body HP's did.

The difference is negligible When you reduce the weight. A-bodies had the same cam the RR and SB packages had in the 383 versions! JMO!
 
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