Exhaust for a 1973 Duster 340 (Pics Included)

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Gold Crusader

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Hey guys!
I am buying my very first muscle car! Been wanting one since I was 5 and now that I'm 26 I have the money! I'm so excited I can't stand it. Five more days... I just can't stop looking up youtube videos!

It's a 340 wedge but I understand the wedge makes no difference but was just marketing? Or it does have some slight variation.

Anyways, about the exhaust. The car comes with absolutely no exhaust and I have no real idea of what I'm doing. I'm in Texas so I am unaware of any laws that I need to be aware of. I know I don't need to worry about emissions but what about loudness? Are there any kits specifically made for the 73 Duster? Any tips or ideas of what I should get? I've never done this before and so this will be my first project. To get it street legal I just need the exhaust and a few bulbs.
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It does have manifolds...that is "some" exhaust
That alone with some downpipes and the kit puppy mentioned are fine

After that, it becomes a checkbook decision
 
Since you have manifolds, a trip to a local exhaust shop, and have them bend you up a set of duels.
 
In answer to the first question:

The REASON the wedge name got started was when the first factory performance 413's came out ?62? were called "Maximum Performance Wedge" or "Max wedge." This "name" became almost a necessity because in 64 you had both a 426 wedge and a 426 hemi, that is, a time when two vastly different engines were the same CID. You could NOT just tell someone "it's a 426", as in "it's a Chivvy 427" because you HAD to get across the STATUS that "it's a hemi" or "it's a max wedge."

So AFTER there were no identification problems, IE there was no 340 hemi, "wedge" just became an excuse to paste a sticker on a loudly painted factory ride.

Curious: What makes you think it's a 340?

I'm not an expert on the matter...or even a slow drip under no pressure at all...but the lack of a vacuum boost on the brakes is one thing that makes me wonder.
 
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All 340's were wedge, its a marketing ploy. That decal is not correct for 73 anyways, someone liked it so they put it on the car.
 
In answer to the first question:



Curious: What makes you think it's a 340?

I'm not an expert on the matter...or even a slow drip under no pressure at all...but the lack of a vacuum boost on the brakes is one thing that makes me wonder.
I have seen more 340 cars without power brakes, than with them.
 
I have seen more 340 cars without power brakes, than with them.

Yes, seems that was the norm. I guess money was tight after the engine upgrade so they settled for manual brakes. Not many 340 cars had AC either.
 
You can do headers if you want, but if the engine is stock or close to it, I would just come off the manifolds with a good dual exhaust system with something like Dynomax Ultraflow mufflers with tail pipes in the stock location.
 
You can do headers if you want, but if the engine is stock or close to it, I would just come off the manifolds with a good dual exhaust system with something like Dynomax Ultraflow mufflers with tail pipes in the stock location.
Ya I heard a lot of people like the Dynomax Ultraflows. So, would I just need to buy the mufflers and have the shop do the rest?
 
I'm in Texas so I am unaware of any laws that I need to be aware of. I know I don't need to worry about emissions but what about loudness?

Texas laws and federal laws are quite different. Federal law says you may not 'delete' the catalytic converter(s). State laws in texas even vary by county. There may not even be a visual inspection required depending on your county.

Sound ordinances are usually town or township based and are rarely enforced. You really have to look or act obnoxious to get a ticket for loud exhaust in most towns. So the sound you choose be can and should be what you like.

As far as what exhaust you pick, you can spend very little or you can spend a lot. The better exhaust kits will be mandrel bent piping and allow your engine to breath better and free up anywhere from 10-50 hp. It all depends on how much hp the motor is to start with. The muffler you choose has much less affect on the performance than the pipes do. Local shops and cheap online sources use compression bent piping that flow poorly. Again, it's all about your situation, your budget, your driving habits etc.

I'd like you to take a look at this exhaust system as an option for your Duster.

67-73 Mopar A-Body 2.5" Crossmember Back w/ X-Pipe System SMA10

If you are interested, PM me for a special member price.

Good luck with your new Duster!
 
73 did not have catalytic converters.
Texas law used to be that the exhaust has to exit the body. In other words you cannot dump the exhaust in front of the rear axle and be legal. That's why you see a lot of side pipes in Texas.
 
Pypes only makes from headers back and not to exhaust manifolds. They were at Englishtown and I asked and that was their response. If you have head pipes off manifolds maybe you could adapt them.
 
Pypes only makes from headers back and not to exhaust manifolds. They were at Englishtown and I asked and that was their response. If you have head pipes off manifolds maybe you could adapt them.
Good point. I should have mentioned that but someone mentioned headers so I was kind of picturing an upgrade to headers which would be a good option. Pypes is also interested in making a nice pair of 340 manifold downpipes for the duster if someone wants to let us borrow their Duster for a bit. :)
 
There are a lot of options for exhaust. Some expensive, some not so bad. This depends if you can do it yourself and you have a shop to work out of, and can use something prefabricated that bolts or welds together. If you're like most 26 year old guys with their first muscle car, budget is an issue. Drag it down to the local muffler shop. They should be able to get you fixed up from the manifolds back, affordably.
 
Good point. I should have mentioned that but someone mentioned headers so I was kind of picturing an upgrade to headers which would be a good option. Pypes is also interested in making a nice pair of 340 manifold downpipes for the duster if someone wants to let us borrow their Duster for a bit. :)
Why you hating on Darts and Scamps? :poke:
 
Ya I heard a lot of people like the Dynomax Ultraflows. So, would I just need to buy the mufflers and have the shop do the rest?
They're great mufflers and sound amazing. But there's nothing wrong with the muffler shop stock $20 turbos either. They certainly won't last as long as a good stainless muffler. Just to get you going.
 
They're great mufflers and sound amazing. But there's nothing wrong with the muffler shop stock $20 turbos either. They certainly won't last as long as a good stainless muffler. Just to get you going.
Thank you so much! I do have it in my budget to get a nice set of mufflers :) However, I'm sorry but I'm still a little confused. I take it to the shop with just the mufflers and just have them add the pipe? Will it be just straight pipe or an x pipe or an H pipe? I'm the epidomy of a noob here lol I really appreciate all this help
 
Thank you so much! I do have it in my budget to get a nice set of mufflers :) However, I'm sorry but I'm still a little confused. I take it to the shop with just the mufflers and just have them add the pipe? Will it be just straight pipe or an x pipe or an H pipe? I'm the epidomy of a noob here lol I really appreciate all this help
If it is anything near a good shop they will just take the mufflers and make the rest up for you. They have to be able to bend the pipe themselves.

Are you staying with exhaust manifolds?

Oh! Welcome to the MoPar club and its madness!
 
If it is anything near a good shop they will just take the mufflers and make the rest up for you. They have to be able to bend the pipe themselves.

Are you staying with exhaust manifolds?

Oh! Welcome to the MoPar club and its madness!
Thank you! Everyone has been so helpful! Also, I’ve done som research and apparently headers wouldn’t have as much compression freeing up for hp? If that’s the case then I’d like to invest in headers.
 
I’ve done som research and apparently headers wouldn’t have as much compression freeing up for hp?
Compression? That word is associated with the engines “compression ratio.” Perhaps you mean the exhausts “back pressure?”
If that’s the case then I’d like to invest in headers.
Headers as well as the rest of the exhaust help reduce if not eliminate back pressure. Anybody, and I really mean anybody, tells you that you need exhaust back pressure, just smile and walk away, quickly, actually, run your *** off like there is a pending bomb in your *** checks.

A member above made an excellent suggestion with Hooker or Summit headers and there exhaust kit. I suggest the exhaust kit at 2-1/2 inches and! Purchase there “H” pipe kit to splice in. A chop saw or any circular power saw with a metal blade for quick, clean and straight cuts is advisable. A chop saw works best.

This do it yourself “kit” is EZ to do and a beginner can do it. If it is your first time, it may take two days. When your old and wrinkly riddled with arthritis and bulging disks like me, it takes half a day. I’ve done it a lot for myself and friends.

Measure twice, cut once!
A sharpie helps A LOT!
 
Page 4 of this old thread shows some of the Hooker headers + Jets exhaust (same as Summit’s exhaust kit) minor trimming needed.

rumblefish's Duster project

The summit exhaust kit comes with mufflers, Jets has the option without mufflers.
 
....I still want to know why it's 'known' to be a 340..... 'Lots of 340s had manual brakes...' didn't answer the question as to the '73 part of the equation.

Not that a 318 can't be fun. If someone is expecting 'x' amount of performance from an engine, it helps to know what they're starting with.

OK. I'll ask. What's the VIN number? Does it match the title VIN?

The VIN doesn't say it's a 340 or not, but puts a direction-of-lean on the sitchiatiown.

No one with any comment on the stripes? As in.....they aren't Mopar stripes is my bet. Not that this makes it gospel, but I've never seen anything like 'em.

Not trying to rain on anyone's parade. Just looking for the facts of the matter. The OP is likely paying a lot more money it being a 340 than if it was the 340's little brother.
 
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