340 vs 360 confirmation

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rumblefish360 said:
In ‘74, the 360 made it into the Duster. Not what I’d call a peppy engine year for any car.
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In 74, the incoming 360-4bbl was rated at the same power as the outgoing 73 340-4bbl. and from my memory with the 74 Sport I once had, I believe it.
But it had 20 cubic inches worth of more torque at the bottom. Something the 340 could never touch.
So I guess your idea of peppy is not the same as mine,

I've had a lot of 340 cars in 50 plus years of driving, and bottom-end peppy is one thing they never had. And that's why, all but one, have had manual transmissions behind them.
Whereas even a 2bbl 360 was more peppy in the daily-driver, bottom-end department.
 
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Woodsman341 said:
I picked them up yesterday, along with a set of '75 high back bucket seats with tracks in very good condition , the stainless drip rails and wheel moldings (all in excellent condition), hood hinges, AC compressor brackets, hood bracing, an emblem or two, and a few other detail bits I was missing, all for almost nothing. Just a local Mopar guy, "friend of a friend" - now a friend after this past week - who was looking to help out instead of get rich. I'm amazed how supportive Mopar folks are of each other, in person and here.
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Is your car a 75 model year? Those seat tracks you picked up are slightly different on the drivers side to account for the different floor pan to house the catalytic converter below compared to the earlier year seat tracks.
 
H22A4 said:
Is your car a 75 model year? Those seat tracks you picked up are slightly different on the drivers side to account for the different floor pan to house the catalytic converter below compared to the earlier year seat tracks.
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It is a 1975 Dart Sport. I haven't put them in yet because it's further down the line, but I guess I should try so I can find the right seat track of I need to!
 
AJ/FormS said:
In 74, the incoming 360-4bbl was rated at the same power as the outgoing 73 340-4bbl. and from my memory with the 74 Sport I once had, I believe it.
But it had 20 cubic inches worth of more torque at the bottom. Something the 340 could never touch.
So I guess your idea of peppy is not the same as mine,

I've had a lot of 340 cars in 50 plus years of driving, and bottom-end peppy is one thing they never had. And that's why, all but one, have had manual transmissions behind them.
Whereas even a 2bbl 360 was more peppy in the daily-driver, bottom-end department.
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the 73 340 was a dog as well
 
Woodsman341 said:
It is a 1975 Dart Sport. I haven't put them in yet because it's further down the line, but I guess I should try so I can find the right seat track of I need to!
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If you’re putting 75 seats in a 75 car then you should be good to go. Double check now to be sure though. It’s the inner track on the drivers side that changed to reflect the added hump in the floor for the cat.
 
H22A4 said:
If you’re putting 75 seats in a 75 car then you should be good to go. Double check now to be sure though. It’s the inner track on the drivers side that changed to reflect the added hump in the floor for the cat.
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Thanks, that detail helps me a lot.
 
H22A4 said:
If you’re putting 75 seats in a 75 car then you should be good to go. Double check now to be sure though. It’s the inner track on the drivers side that changed to reflect the added hump in the floor for the cat.
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I checked with the guy I got the seats and tracks from, and he's almost certain the seats are '75, but thinks the tracks may be '74. In addition, I currently have a bench seat...so I think I may have a modification or two in my future. At the very least, it looks like I have more research to do, or just take the bench out and see what I can see.
 
H22A4 said:
If you’re putting 75 seats in a 75 car then you should be good to go. Double check now to be sure though. It’s the inner track on the drivers side that changed to reflect the added hump in the floor for the cat.
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I don't suppose you have any pictures? I've googled til my eyes hurt but all I see are 70-72 tracks, which look like the ones I have as far as I can tell.

Oh, and the ProCar tracks look nothing like mine.

Last thing: were the inner and outer tracks linked? Mine has a side with the lever and lock, the other is a dummy track.


Either way, thanks for the info!
 
H22A4 said:
Here’s a post showing what the ´75/76 drivers seat inner track looks like. Is your the same?
[WANTED] - 75 76 bucket seat tracks Catalytic converter style
And another similar thread about the difference in the 75/76 drivers bucket seat inner track.
Converting 75 Scamp to bucket seats
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Unfortunately, no, both of mine look like the attached photo (the pic is from Classic Industries, I'm not home to get a pic of my actual, somewhat well-loved tracks). :) From the links you shared, it doesn't look like it would be hard to fabricate the correct track, if I can't locate an actual one that is.

Thanks again for everything.

Screenshot_20240223-143802.png
 
Step headers are the way to go with an A-body and they are far better than any stock exhaust system. I once had some Hooker comp headers on my 340 automatic Duster and they were somewhat flattened on one of the drivers side tubes and the Duster still ran like a raped ape. Headers even damaged ones will out perform stock manifolds.
 
Bubblegum said:
Step headers are the way to go with an A-body and they are far better than any stock exhaust system. I once had some Hooker comp headers on my 340 automatic Duster and they were somewhat flattened on one of the drivers side tubes and the Duster still ran like a raped ape. Headers even damaged ones will out perform stock manifolds.
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Step headers? That's a new one on me...it looks like I have some Googling to do. :)
 
Bubblegum said:
Step headers are the way to go with an A-body and they are far better than any stock exhaust system. I once had some Hooker comp headers on my 340 automatic Duster and they were somewhat flattened on one of the drivers side tubes and the Duster still ran like a raped ape. Headers even damaged ones will out perform stock manifolds.
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Also, any names or links?

Thanks!
 
Bubblegum said:
TTI sells step headers for A-Body Mopars.
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I checked them out, and they are just a variation on standard long tube headers. While I understand they would provide certain performance advantages, for my intended build they would likely be more trouble than any benefit they might provide. Thanks, though!
 
273 said:
https://www.motortrend.com/how-to/mopp-0307-installing-exhaust-headers-into-300hp-crate-engine/

Dyno shootout of manifolds and headers on a 300 hp 5.9l

Horsepower​
RPM318360340SHT1 58tti1 34
2500186185187189187189187
3000223223225226228228226
3500269271272276280281279
4000299301306307314318312
4500311313315321319326321
4600211314315320317327319
5000303304308315312316311
5400281291289295282296289



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So, if I'm reading this correctly, my 360, using the 340 manifolds, will produce 315hp max, and changing to the awesome (but expensive) TTI headers gives a gain of 12hp. I understand that if I were racing or just looking for bragging rights then sure, TTI headers are the way to go, but typical street use wouldn't make any practical difference. And yeah, I decided a long time ago that if I were going to use headers, it would have to be TTI for fitment, especially their slip-tube design.

I still think that using 340 manifolds on my mild 360 build is the right thing for me, but who knows? I may run into some money later or decide to up the power on the build and go a different way. In any case, I really appreciate the information from all of your perspectives!
 
Woodsman341 said:
So, if I'm reading this correctly, my 360, using the 340 manifolds, will produce 315hp max, and changing to the awesome (but expensive) TTI headers gives a gain of 12hp. I understand that if I were racing or just looking for bragging rights then sure, TTI headers are the way to go, but typical street use wouldn't make any practical difference. And yeah, I decided a long time ago that if I were going to use headers, it would have to be TTI for fitment, especially their slip-tube design.

I still think that using 340 manifolds on my mild 360 build is the right thing for me, but who knows? I may run into some money later or decide to up the power on the build and go a different way. In any case, I really appreciate the information from all of your perspectives!
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Of course it is
much better places to spend 1k bucks for tti 12hp
nitrous 900 bucks=rocket ship
on demand
light weight
 
AJ/FormS said:
For a streeter, The cam and gears combo will pretty much dictate if the headers are gonna be a big deal.
IIRC the early 340 cars picked up something like 30 odd horsepower with headers, but up around 5000/5200. So if you had 3.23 gears with a TF auto, you might not get to 5000 in Second gear, until 77mph ..
But if a 4speed and 3.91s, then 5000 in Second is 53mph, now the cam wants headers, cuz 77 will be top of Third gear and flying!.
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the early cars did not pickup 30 hp
15 tops 10 to 12
changing to 2.5 pipes was all it needed
nick just showed another dyno test 340hp stock manifolds 750 avs2
 
Woodsman341 said:
So, if I'm reading this correctly, my 360, using the 340 manifolds, will produce 315hp max, and changing to the awesome (but expensive) TTI headers gives a gain of 12hp. I understand that if I were racing or just looking for bragging rights then sure, TTI headers are the way to go, but typical street use wouldn't make any practical difference. And yeah, I decided a long time ago that if I were going to use headers, it would have to be TTI for fitment, especially their slip-tube design.

I still think that using 340 manifolds on my mild 360 build is the right thing for me, but who knows? I may run into some money later or decide to up the power on the build and go a different way. In any case, I really appreciate the information from all of your perspectives!
Click to expand...
Modest gains on milder engines yes. With a large cam high flow head and/or stroker then headers can gain 50 hp or so over manifolds. So how much hp headers gain depends on engine combo.

If you go with TTI exhaust with manifolds then decide later want headers you can pull head pipes out of H pipe and swap in shorty pipes to hook to headers. Thats what I did I used to run 340 manifolds then when orig eng got replaced with stroker eng switched to headers.

PXL_20240216_235936745.jpg
 
340sFastback said:
Modest gains on milder engines yes. With a large cam high flow head and/or stroker then headers can gain 50 hp or so over manifolds. So how much hp headers gain depends on engine combo.

If you go with TTI exhaust with manifolds then decide later want headers you can pull head pipes out of H pipe and swap in shorty pipes to hook to headers. Thats what I did I used to run 340 manifolds then when orig eng got replaced with stroker eng switched to headers.

View attachment 1716213880
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I hadn't considered that...that's kind of a good option, especially since the car at present has NO exhaust system, just craptastic headers and glass packs that dump under the seat area.
 
TTI will give a stock or mild build up to 20 extra horses easy. Do not undersell the TTI headers. Go with straight through mufflers and shortened exhaust system and you will get an other 20 to 30 more horses especially if the pipes are 3 inches but 2 and half will work good too! I once had 1 an 3 quarter going into 3 inch with 4 inch tips out the sides in front of the rear tires. I f you have at least 391 gears or better and a 3 or 4 speed manual transmission and you can get them to fit 1 and 7/8 inch headers will also work.
 
Woodsman341 said:
Would I be correct in assuming that any of the stock exhaust manifolds for an early 70s 340 will flow better than the mid 70s and late 70s 360 stock manifolds? I have a chance to pick up some 72 to 73 340 manifolds dirt cheap.

Since I'm building a daily driver I'm going to ditch these awful headers. I'm not saying all headers are awful, but the ones I currently own definitely are!

Thanks again folks.
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The 72-73 340 manifolds will work just fine, but make sure the drivers side is for an A body. Passenger side is the same between A, B and E bodies, but the drivers side is specific for A body cars. The only difference between a 68-70 drivers side 340 HP manifold and a 72-76 340/360 drivers side manifold is the later ones have bolt bosses cast in to hold the heat stove that the heat tube going up to the air cleaner hooks to.
 
JDMopar said:
The 72-73 340 manifolds will work just fine, but make sure the drivers side is for an A body. Passenger side is the same between A, B and E bodies, but the drivers side is specific for A body cars. The only difference between a 68-70 drivers side 340 HP manifold and a 72-76 340/360 drivers side manifold is the later ones have bolt bosses cast in to hold the heat stove that the heat tube going up to the air cleaner hooks to.
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I got the right ones, and as I said, at an amazing price. I also got a set of A Body buckets along with a hundred pounds of other cool Mopar goodies. :)
 
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