Hey guys, I need advise on what each manifolds can be ran on a 318-360 in 72 duster. I plan to put 360 heads on 318 and want to use manifolds instead of headers for price savings and I have a set of center dump but not sure they will fit they might work on pass side but not much room on driver side, I am running manual PS gear box with the small starter. Any ideas ? Thanks
Manifold questions
- Thread starter gnr
- Start date
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HP 340 manifolds are the choice. What number head do you have on now and which heads are you going with?
I was curious on the head numbers. Bigger ports won't necessarily make more power if the combustion chambers are too big and compression is lost.
Treblig
Well-Known Member
Not claiming to know what's best but I changed manifold gasket on the original and was blown away how small ports were,. I heard running 360 heads were a bad idea cause chamber size but I should be ok if heads have been planned. On a serious budget ,. Project with my son's and I want them to help pay for things so they know money doesn't grow on trees They are 14 and one almost 16
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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Many years ago,I put a 69-340 top end on a stock 73Dart, low compression teener, and there was no saving that turd. With the stock low-stall TC and 2.76s it was a disaster.It was a slug off the line as compared to the factory 2bbl top end.The power didn't come on until about 40 mph,and then the stock cam gave up. But hey it had pretty good passing power.....at 80mph. Or at least it sounded like it did. So I did the obvious, I put the 340 cam in it. And that took it from bad to worse.
On that very same teener short block;many more years later, and now wearing its factory heads and cam, I tried something else. I put headers on it,a TQ, 3.55s and a 2400TC. I also installed a wide-ratio 904.Now pushing 3850 pounds, it was a whole different much funner car. (The 73 Dart was long gone to the shredder).
So, I know you didn't ask;but
If you wanna perk up the teener may I suggest gears and a higher stall TC, plus a 4bbl, on the stock long block. And of course dual exhaust. It will be waaay more bang for the buck.Waaay more. At least 3.55s and at least 2400. And I love TQs, and so do teeners! A pair of Treblegs Bigmouth exhaust manifolds would be icing on the cake! But I wouldn't be in a hurry to change them out with the teener heads, 2.76s, and duals. And the reason is cuz, the gearing is so bad (11.2mph per 1000rpm),that first gear is good to about [email protected] the teener iron manifolds can probably breath most of the way there. And then you hit second gear for a bit and you're done.And if you go with 3.55s and a 2800TC, the teener will be much more lightly loaded in first gear, and still be ok for most of that gear. Now, headers that's a whole nuther story. Most of the time headers is the number 1 very first thing to install.
So if you are on a budget;gears,TC, and dual exhaust.Oh yeah put some springs on those valves to get the Rs up to at least 5200. 5500 is better.If you can swing headers, I would do those waaay before 340 heads, planed or not.And I would put a good used 360 cam in there still before heads. Cuz those big-valve heads need taller pistons.
Ok so that's what I earned.
On that very same teener short block;many more years later, and now wearing its factory heads and cam, I tried something else. I put headers on it,a TQ, 3.55s and a 2400TC. I also installed a wide-ratio 904.Now pushing 3850 pounds, it was a whole different much funner car. (The 73 Dart was long gone to the shredder).
So, I know you didn't ask;but
If you wanna perk up the teener may I suggest gears and a higher stall TC, plus a 4bbl, on the stock long block. And of course dual exhaust. It will be waaay more bang for the buck.Waaay more. At least 3.55s and at least 2400. And I love TQs, and so do teeners! A pair of Treblegs Bigmouth exhaust manifolds would be icing on the cake! But I wouldn't be in a hurry to change them out with the teener heads, 2.76s, and duals. And the reason is cuz, the gearing is so bad (11.2mph per 1000rpm),that first gear is good to about [email protected] the teener iron manifolds can probably breath most of the way there. And then you hit second gear for a bit and you're done.And if you go with 3.55s and a 2800TC, the teener will be much more lightly loaded in first gear, and still be ok for most of that gear. Now, headers that's a whole nuther story. Most of the time headers is the number 1 very first thing to install.
So if you are on a budget;gears,TC, and dual exhaust.Oh yeah put some springs on those valves to get the Rs up to at least 5200. 5500 is better.If you can swing headers, I would do those waaay before 340 heads, planed or not.And I would put a good used 360 cam in there still before heads. Cuz those big-valve heads need taller pistons.
Ok so that's what I earned.
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Treblig
Well-Known Member
exhaust manifolds from any small block E or B body will work great with your manual steering. You can order the down pipes (head pipes) 2.5 inch from TTI that will end at about the cross member.
example on one of my dusters.
Treblig
Well-Known Member
Well.....I missed the part about the OP having manual steering!! Good catch, if "gnr" can use the smaller manifolds it would save some money. I have a few of the 340 (smaller hole manifolds), they are 1 7/8" exit hole. "gnr" has already PMed me looking for some 340/360 manifolds. Although I do have some 340/360 manifolds he could save money by buying the 340 (smaller hole) manifolds.
Just in case "gnr" doesn't know....stock 318 manifolds have a 1 5/8" exit hole, 340 (small hole) manifolds have a bigger 1 7/8" exit hole and the 340/360 manifolds I sell have the largest 2 1/4" plus exit holes.
treblig
You should take the downpipe for the 360 mag manifold side and make copies. I bet you'd sell one per manifold sold. Or even folks that got there own manifold might buy one.
Treblig
Well-Known Member
I do make those and sell them, with the manifolds and also sell them as singles. The 360 bell shaped down pipe isn't sold anywhere that I know of. The "factory" salvage yard down pipes are swedged down just behind the flare so they aren't any good for flow. The factory down pipes are also made of smaller pipe. So I buy sections of 2 1/4" pipe and have the pipe flared at a muffler shop. Then, since no muffler shops have the "factory" flaring dies, I take the flared pipe home and hammer (peen) the straight flare into a bell flare (just like the factory) using a 360 magnum manifold as a die form. I also sell the flange adapter which is hard to find. It's hardly worth all the the trouble for what I sell them for but......people need them so I make and sell them, just like the 340, 120 degree down pipe.
In these pics you can see the factory (rusty) bell flared pipe. It's made out of much smaller pipe then it's necked down again making it unusable for good flow.
treblig
How far down do your head pipes go? How much do you sell them for? thanks
Treblig
Well-Known Member
The 340 120 degree "flat flared" down pipe with 340 flange adapter sells for $75 (plus shipping). Each one is hand made. The 360 "bell flared" down pipe with flange adapter sells for $30 (plus shipping). The 340 down pipe is pretty short, I make it so that you can clear the torsion bar without choking down the pipe, I use 2 1/2" mandrel bend pipe. It's not very long. Any muffler shop can make the rest of the piping on the driver's side. The only place they have problems is where the pipe needs to clear the torsion bar, so I make that part. The only way a muffler shop can make a piece of pipe that will clear the torsion bar is by crushing the pipe so bad that it cuts off the flow. Since the 340 requires a flat flare so close to the super sharp bend most muffler shops can't make it at all.
The 360 down pipe can be from 12 inches to 18 inches long. The driver's side 360 manifold down pipe is very accessible and any muffler shop can make good flowing pipes because there is plenty of room where the 360 manifold exits.
In the case of my '69 Barracuda, I bought a section of mandrel bent J pipe and cut and welded it in place coming off the 120 degree 340 down pipe. Then I removed it and finished all the welds. The passenger's side was much easier.
treblig
Treblig
Well-Known Member
Thanks for the great POSITIVE FEEDBACK RATING on the 360 down pipe I sold you!!!!
Treblig
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