318 build #2 "cost minded" for the '74 Duster

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273 said:
There is another dyno test between manifolds and found that best combo was one 340 and one 5.9l forget which ones but here's non magnum manifold and header shoot out

Installing Exhaust Headers Into 300hp Crate Engine - Mopar Muscle Magazine
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Oh yes! Thanks remember. Well, on THAT particular combo, the 360/300, the call of exhaust is for the owner. 311 or 327 hp, 403 or 425 ft lbs of tq.
That’s 16 hp & 22 fr lbs of tq to decide on between exhaust manifolds and tti headers. Which will make more power once you out there exhaust system on. They stated no collector extentions on the headers. All on a stock engine.

No Magnum manifolds tested. So I’d still like to see what that deal is worth. Anybody?

The factory writings stated the best exhaust manifold combo was the drivers 340 & Magnums passengers side. I still see it loosing to headers. But the owner/operator & spender of money will have to decide if it is worth it.
 
rumblefish360 said:
Oh yes! Thanks remember. Well, on THAT particular combo, the 360/300, the call of exhaust is for the owner. 311 or 327 hp, 403 or 425 ft lbs of tq.
That’s 16 hp & 22 fr lbs of tq to decide on between exhaust manifolds and tti headers. Which will make more power once you out there exhaust system on. They stated no collector extentions on the headers. All on a stock engine.

No Magnum manifolds tested. So I’d still like to see what that deal is worth. Anybody?

The factory writings stated the best exhaust manifold combo was the drivers 340 & Magnums passengers side. I still see it loosing to headers. But the owner/operator & spender of money will have to decide if it is worth it.
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If I remember right the magnums made 1-2 hp over 340 and the 340/5.9 combo made like 1-2 hp over that. I'm pretty sure was done by one of the mopar magazines but been unable to find it.
 
I'd have to send that stock converter off to be "loosened up" some. I'm certain it would buy you 2 tenths in the 60 foot and you can still call it a Stock converter. Furthermore it would have no negative side effects to the goal of your build.
 
rumblefish360 said:
I don’t think 318WR has a sh#%in thing to prove but what he is doing is having fun while showing the world. He has a nice following on his UT-channel by having fun.
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We are doing what we'd be doing if there was no internet. As you stated, we are just having fun. We share the build because somebody, somewhere may find something useful from this build.
 
318willrun said:
We are doing what we'd be doing if there was no internet. As you stated, we are just having fun. We share the build because somebody, somewhere may find something useful from this build.
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Freakin A dude! Freakin A!

If ya not having fun doing it, then your ether doing it wrong or your not really interested in what your doing. You keep on doing what your doing. I tune into & enjoy your channel.
 
Ok, so I haven't read all 100 pages of this thread. But if you want economy you need lean mixture at cruise. If you don't have one already get a wideband O2 sensor and work on getting that cruise lean. Get it up in the 15's. That will help tremendously with the economy.
 
Headers almost always pick up torque over manifolds, in the lower midrange up to midrange. I've never had a situation where I didn't notice a definite improvement going from manifolds. I think some of the shorty style headers are pretty worthless though. Gotta get the long tubes.
 
@318willrun Love your channel. Going to be an interesting build. You may need to add another $5 to the project to help with mileage.

Would love to see a comparison with the duals back on top the motor when all is said and done. If you end up with the LA heads.
 
Mopar44134 said:
@318willrun Love your channel. Going to be an interesting build. You may need to add another $5 to the project to help with mileage.

Would love to see a comparison with the duals back on top the motor when all is said and done. If you end up with the LA heads.
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Thanks, we appreciate it! And for those that don't watch my channel and the "5 dollar" remark doesn't make any sense, it's the 5 dollar fan on the van in which he speaks!!!! LOL :D
 
1971 CY Dodge Dart said:
Headers didn't seem to make much of a difference on this combo over manifolds.
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I agree because it is a stock small engine. MP just outfitted what is basically a OEM 5.9 Magnum with a carburetor intake, 750 carb & 1-3/4 headers to get what they did and label it as 300hp as not to disappoint anyone when it dyno’s more.

All stock V8 engines gain power with dual exhaust and header a wee bit more. The big deal of headers isn’t so big on the above but becomes a wider and wider gap as the power goes up.

Headers were always a great first step.
 
rumblefish360 said:
I agree because it is a stock small engine. MP just outfitted what is basically a OEM 5.9 Magnum with a carburetor intake, 750 carb & 1-3/4 headers to get what they did and label it as 300hp as not to disappoint anyone when it dyno’s more.

All stock V8 engines gain power with dual exhaust and header a wee bit more. The big deal of headers isn’t so big on the above but becomes a wider and wider gap as the power goes up.

Headers were always a great first step.
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I 100% agree but a couple guys are in the 10s with manifolds
nothing better then beating built cars ford and chevys then pop the hood and say like my stock manifolds
 
Oh! That F.A.S.T class and such, sure! If you don’t mind giving up a 100+ hp using exhaust manifolds, go for it.
I never said you can’t go fast with exhaust manifolds.
 
Now that intake think about it, when I was in my early 20’s, I met a fella with a tunnel ram equipped 340 running exhaust manifolds on a 340 that ran in the 9’s. The car was a - IIRC - a Cricket. This was ‘88/‘89.
 
rumblefish360 said:
Oh! That F.A.S.T class and such, sure! If you don’t mind giving up a 100+ hp using exhaust manifolds, go for it.
I never said you can’t go fast with exhaust manifolds.
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never said you did thats why i agreeded with you
think its more like 60 or 70 hp but alot
 
Just saying…. Often posters lead with such statements to start an argument with me.
 
rumblefish360 said:
Just saying…. Often posters lead with such statements to start an argument with me.
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iam trying to stay away from that bs
comments such as
thats about as usefull as a sunroof in a submarine
iam new here but been lurking awhile
same as any other forum ive been on
 
We have more big component parts coming and some already here. More to share with you guys in the near future. I am super excited for this build! I'm only sorry I got started so late in the year.
 
Well don’t push yourself, no need to freeze your fingers off doing work on the car, etc….
 
318willrun said:
I know somebody that bought a brand new 340 Demon with auto and 3.91's. All they did, and ALL they did was bolt slicks on it and it ran 14.20's factory bone stock with zero spin. But that isn't 13.9's. And that's not with 2.94's. lol
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Speaking of tires, there is a lot to gain in terms of mileage with the right ones.

Since you are doing a regrind, maybe talk with Oregon about a dual pattern cam to help crutch the exhaust with your stock manifolds. Are the manifolds 318 or 360?

Whoops never mind about the regrind comment I see you have a comp cam already.

If you do nothing else to help compression at least run the Mr. Gasket .028 head gaskets.

Also another question- is your converter lock up or no? Obv 904 l/u would help mileage.
 
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Rat Bastid said:
The question is what was the MPH? The ET doesn’t mean much. If you don’t know the MPH and the weight you have no clue what power it’s making.
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yup trap mph and weight tell the story stingyest dyno there is
 
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