TTi step vs. 340 manifolds

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go-fish

go-fish

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Stock 1973 340 with Z and O head. LD340 intake. Power steering
Should I keep the manifolds or go through the hassle of fitting my TTi step headers around my torsion bars and p/s box. The car will have 3.23’s so it’s not like a max effort kinda car. There’s also the expense of new exhaust pipes. I would also have to buy another set of headers because these TTi’s were bought for a different project so that’s another $800 I would have to spend.

Is it worth it or with the combo it is would the manifolds be just as efficient?

This is a decision point between being economic with my parts and purchases and completing the combination that’s in the car. Is the intake/cam and gearing screaming for a set of headers to let it breathe or will 340 manifolds be enough manifold for the task at hand?


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Does an extra 15-30 hp through out the rpm range matter enough to you ??
 
Manifolds are street friendly.

Headers are not.

So flow or economic considerations aside, how do you intend to use the car?
 
Alaskan_TA said:
Manifolds are street friendly.

Headers are not.

So flow or economic considerations aside, how do you intend to use the car?
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I have a race car project already and this car is numbers matching so keeping it street smart. New paint, very good interior, fold down seat option. Very clean.
My goal has been to only do Day 2 mods aside from an MSD distributor and an under dash MSD 6AL, hence the LD340 and not an Air Gap. I was just planning on the intake and header upgrade. Even the stereo is going to stay AM but with a Bluetooth conversion. Really wanting it to look original. I would make an exception on the TTi’s and the period correct LD340.
 
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I'm sort of in the same boat as you with similar mods. Stock 340 with x-heads and 3.23's. Performer RPM manifold. My manifolds are not the hipo ones though but rather 72-73 dated manifolds with the exhaust coming off the passenger side looking like less than 2". I am for sure doing headers this Winter, just haven't decided yet between TTI's or Doug's. I think you should go with the stepped TTI's.
 
1971 CY Dodge Dart said:
I'm sort of in the same boat as you with similar mods. Stock 340 with x-heads and 3.23's. Performer RPM manifold. My manifolds are not the hipo ones though but rather 72-73 dated manifolds with the exhaust coming off the passenger side looking like less than 2". I am for sure doing headers this Winter, just haven't decided yet between TTI's or Doug's. I think you should go with the stepped TTI's.
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I already have the headers. They are actually for a different car that I was working on before the Duster fell in my lap.
 
You answered your own question in #7. Numbers matching cruisers don't need headers, you have a racecar project to go fast with. Headers will make more power, unquestionably. Do you need more power for your cruiser, especially if you need to buy the headers again?
(Note: I am NOT anti-header, I have three cars with headers. None is remotely a cruiser.)
 
33IMP said:
You answered your own question in #7. Numbers matching cruisers don't need headers, you have a racecar project to go fast with. Headers will make more power, unquestionably. Do you need more power for your cruiser, especially if you need to buy the headers again?
(Note: I am NOT anti-header, I have three cars with headers. None is remotely a cruiser.)
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Totally right. More expense and its just not “needed”. Wanted yes.
 
Manifolds. Enjoy the car at a street cruiser. If you want to make a bunch of smoke, go get in your race car. That's just one persons opinion though....

JW
 
For your application, I like that cam.
It has 50* of overlap, 6 more than the factory 340 hydro.
IDK if you remember the 70s but when the 340 came out, I was in highschool. Quite a few of us had 340 cars.
They were fun lil cars, but we found out real quick that those logs were only good to about 85 mph then the power started falling off fast. To beat other cars, both you and your car, had to be quick off the line; and I always specified a shutdown at 85.
Headers changed all that.
Log manifolds kill the overlap. And mess up the intake manifold. 50 degrees ain't too bad, and a hi-stall will get you past the worst of it.
Assuming your 73 is still at or near 8/1 compression ratio;
>At 111* of power extraction(in at 106), that cam has the potential to make great hi-way fuel economy, once the Rs get up. But around town the overlap will mess things up. >In an 8/1 engine, with an Ica of 61* (in at 106) the bottom end is gonna be pretty soggy; so, with 3.23s I think you will be shopping for a higher stall.
Happy Hotrodding
 
11.71 with manifolds, I know of a duster running 10.66 with manifolds. Headers make more power, the more serious effort the more you lose with manifolds.
 
go-fish said:
I have a race car project already and this car is numbers matching so keeping it street smart. New paint, very good interior, fold down seat option. Very clean.
My goal has been to only do Day 2 mods aside from an MSD distributor and an under dash MSD 6AL, hence the LD340 and not an Air Gap. I was just planning on the intake and header upgrade. Even the stereo is going to stay AM but with a Bluetooth conversion. Really wanting it to look original. I would make an exception on the TTi’s and the period correct LD340.
Click to expand...

Sounds to me like I would ..

Cast exhaust manifolds, paint the intake manifold, stock type orange air cleaner and give up the HP and drive it more.
with 3:23 and assumed auto w/stock convertor that cam might be a little fat,
 
Does anyone repro the "good" 340 manifolds, wonder how price compares to new TTIs?
I think they came on '68-'70 models.
 
70 Buster 340 said:
Sounds to me like I would ..

Cast exhaust manifolds, paint the intake manifold, stock type orange air cleaner and give up the HP and drive it more.
with 3:23 and assumed auto w/stock convertor that cam might be a little fat,
Click to expand...

I do have the stock orange air cleaner. It's in pretty good shape with a hint of patina. I may restore it so it's perfect.

The original 340 and 4 speed are rebuilt.

This car has been intact its whole life and is very close to completion. Not a concourse restoration by any means but pretty a pretty darn good example of a factory restoration.
 
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33IMP said:
You answered your own question in #7. Numbers matching cruisers don't need headers, you have a racecar project to go fast with. Headers will make more power, unquestionably. Do you need more power for your cruiser, especially if you need to buy the headers again?
(Note: I am NOT anti-header, I have three cars with headers. None is remotely a cruiser.)
Click to expand...
Then he should pull off the LD340 too, right? Headers are day 2. Put um on there and reap the benefits.
 
go-fish said:
I have a race car project already and this car is numbers matching so keeping it street smart. New paint, very good interior, fold down seat option. Very clean.
My goal has been to only do Day 2 mods aside from an MSD distributor and an under dash MSD 6AL, hence the LD340 and not an Air Gap. I was just planning on the intake and header upgrade. Even the stereo is going to stay AM but with a Bluetooth conversion. Really wanting it to look original. I would make an exception on the TTi’s and the period correct LD340.
Click to expand...
The LD340 and TTIs together could add 30-40 HP. That right there should answer it. I agree with @abodyjoe that if we were talking about a lesser quality header, leave them on the shelf. We're talking about really good headers. Use um.
 
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Header will gain across the power band and better sound too. TTI and Dougs fit well, hang up tight, don't leak ect unlike some of the low grade junk out there.

If you are die hard stock appearing you could swap to the earlier high flow passengers side manifold remove heat riser, install a non-pinched driver's side head pipe, straight through mufflers such as Dynomax Ultra Flow, and reproduction exhaust tips that don't have that super small inner diameter choking it down. Mandrel bent pipes front to back will also improve flow. So there are significant gains to be had without swapping to headers and maintaining stock appearance.

And if you swap to headers and you have stock exhaust tips if they are anything like what was on my '69 they choke like 1 1/2" inner diameter which is not going to flow what so ever.
 
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