Early a exahust suggestions?

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BJDEALER

BJDEALER

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Ok i am taking to cuda to the exhaust shop finally. It has a 360 with stock 273 manifolds. Its a stock 360 nothing special. I am planning on keeping the manifolds for a while until i can afford custom headers since my car is a power steering car. With those things in mind what is my best exhaust option? I am open to keeping single exhaust since my cross member is not modified for duals.
Thanks for suggestions.
 
single 2.5 with a flowmaster super 40 they also make a flowmsater that has single in and duals out 2 make it look like a dual
 
I'd make a Hipo clone and run 2 inch pipe from the manifolds transitioning to a single 2.5 pipe. Then 2.5 to 2.5 straight thru glass pack then 2.5 up and over the axle to another 2.5 straight thru glass pack as long as will fit, and a tip or pipe out the back. Look at the Accurate LTD website to see what they do with the front Y pipe. Get good glass packs as this will be loud quick if you get cheap glass packs that blow out. Listen to some of the sound clips that are posted.
 
Modify that crossmember and run dual 2-1/4 or 2-1/2 and let that 360 get rid of a little back pressure.
 
I think they refer to using the 273 manifolds as trying to poop through a soda straw, but I seem to remember that even putting duals with glasspacks on my 273 with the stock manifolds really woke it up. Might have just been the noise though. :thumblef:
 
can the muffler shop modify the crossmember in the process? I really dont want to mess with it
 
I had a 66 Canadian Valiant(a US dart) with a 360 with 273 manifolds, we built a 2" Y-pipe in to a 3" single, with a big Walker/Thrush turbo muffler and a 3" single tailpipe. Lots of room for the 3" pipe. The 273 manifolds were defiantely the choke point, but they were the only thing I could afford that would fit the car. Sounded really good, to me anyway.
 
i know how you feel about the stock manifold thing. I would have to get custom headers if i am not mistaken because i have power steering. Thinking about getting a manual steering box someday and converting so i can use durango manifolds which i have laying around. Can i modify the cross member after i have the dual exhaust on?
 
Check TTI's web-site. If you send your cross-member they will notch the right side and re-weld a bottom plate for $100. However, offer is only if you buy their ~$800 headers. Maybe you can beg them to do it for $150 without a purchase.

However, I attach a schematic someone posted that shows a Hi-Po with a single factory exhaust. Interesting, because others show that the way to tell an original Hi-Po is by dual humps in the rear sheet metal. Maybe varied by year or Darts, Valiants, Barracudas. Looks like a single exhaust could be historic for some, though you went 360 anyway.
 

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BJDEALER said:
i know how you feel about the stock manifold thing. I would have to get custom headers if i am not mistaken because i have power steering. Thinking about getting a manual steering box someday and converting so i can use durango manifolds which i have laying around. Can i modify the cross member after i have the dual exhaust on?
Click to expand...

The trans crossover is pretty easy to convert for dual exhaust.
I know a member on this site that would probably do it for you,for a small fee.
You could mail it to him.

340 or magnum manifolds would be nice,but it seems up in the air if they fit the early A.
The best set-up would be a set of tti early A headers, but they can get expensive.
Ditching the power steering helps things as well.
 
dusterglenn said:
I had a 66 Canadian Valiant(a US dart) with a 360 with 273 manifolds, we built a 2" Y-pipe in to a 3" single, with a big Walker/Thrush turbo muffler and a 3" single tailpipe. Lots of room for the 3" pipe. The 273 manifolds were defiantely the choke point, but they were the only thing I could afford that would fit the car. Sounded really good, to me anyway.
Click to expand...

I would do it this way if you don't want to modify the crossmember. Otherwise modify the crossmember and fit some duals with a muffler you like.
 
BJDEALER said:
i know how you feel about the stock manifold thing. I would have to get custom headers if i am not mistaken because i have power steering. Thinking about getting a manual steering box someday and converting so i can use durango manifolds which i have laying around. Can i modify the cross member after i have the dual exhaust on?
Click to expand...

Doug's D450 will fit your car with power steering. Not cheap, but they say they will fit.
 
i jus took my wagon to the muffler shop and asked for fomasters and duel tips out the back besides the 500bucks its great its the 1in 2out.
 
Ok got the exhaust done. I just went with a the hypo single exhaust setup. It sounds pretty good. The only problem is i now know i have an exhaust leak at the manifolds. I am using stock 273 manifolds with my 360. Is there any reason that i should have a leak Do the ports line up? I need help on this one thanks
 
You need to find some Dakota manifolds(360)not sure what year.Hope someone chimes in with the year,but the pass.side fits no problem.The drivers side needs alittle grinding to clear the steering in the early-A,s.Hope this helps.Lose the 273 manifolds on the 360.JMO
 
Check to make sure that the 273 manifolds are flush with the port. As I remember, I had to grind a bit on my "J" head, drivers side, because of interference. Just grind what you need. Some of the guys here have hit coolant passages. If it has egr ports they must be plugged also.
 
Like 66fs said, the driver's side 273 manifold fits very tight to the head. On some later 360 heads, the air injection boss interferes with the manifold. I had to grind some off the head for the manifold to fit flush. You really don't have to take much off to make it fit.
 
Can someone show me where and what to grind down? I hope i can do it with the motor in the car. Thanks for the help
 
It was like 12 years ago when I did mine, and I can't honestly remember if it was the air injection boss on the head, or the side of the block that was the issue.
With the manifold unbolted from the pipe, and the gasket out of the way you should be able to see or feel where the manifold is hanging up.
 
not sure what the air injection boss is. I know my heads have holes that are plugged up that were air injection purposes but they have small allen plugs in them is that what you are talking about? This sucks but gonna have to fix it
 
On the "J" heads I had to grind on the lower boss for the head bolts. Sometimes you have to remove the exhaust manifold that is leaking, clean up the mating surfaces and trial fit to see if there is anything that keeps the manifold from sealing to the ports. maybe an allen plug, maybe the boss that the allen plugs thread into. I think the manifold should seal the port as my 66 273 manifold sealed to the "J" heads. I also use Copper colored Hi Temp RTV to help seal the exhaust.
 
BJDEALER said:
not sure what the air injection boss is. I know my heads have holes that are plugged up that were air injection purposes but they have small allen plugs in them is that what you are talking about? This sucks but gonna have to fix it
Click to expand...

To bad you had to leave the 273 manifolds on,your really choking your 360.

Having said that,first thing you need to do is take the manifolds off,and make sure all your air injection (holes) in the 360 heads are blocked/sealed.
Allen plugs with a high heat sealant. These need to be sealed first. The exh man gasket "does not" seal these.

Second,look at all mating surfaces,and make sure they are flat,with nothing protruding out.Use a wire wheel,file,to smoothen any rough spots,if you cant take them out of the car.Put rags in the cylinder head holes,so no debris goes in.When finished, clean with accetone.

Third,look for a set of high quality/thick 273 exhaust manifold gaskets.
No sealant should be necessary.
Put them on,torque to factory specs,drive,let cool,re-torque,and you should be good to go.
 
Sorry, by 'air injection boss' I mean the raised casting that the air injection holes are located in. The outlet for the left side mainfold curves in very close to the lower edge of the head, and the 70's/80's head has those raised castings/bosses that the 60's head didn't. The outlet of the manifold will hit the boss before the flange fits flush to the head.
 
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