I might be buying a 318 with milled down 360 heads. What i need to know is whether 273-318 exhaust manifolds will fit the 360 heads? the reason i ask is because i need a special type of exhaust manifold to clear my steering box. It's the kind from the dodge dart plymouth valliant. it looks like this: i just need to know if it will match up or if i'll need to find another solution. thanks.
Helps if you use the correct gasket/heat shield on that side.... anyways, yeah, they'll bolt on, but the ports will be way mismatched. See if you can find some Dart (A body) 340 manifolds. Might be a bit expensive.
Was thinking of doing this very thing (with 73 340) before I decided to keep the slant six (4+ dollar fuel last summer). There were manifolds produced in 68-74 designed for this very application to fit the big port X and J 340 (68-72) and later 340-360 (73-5) heads, but the 318 ones will bolt on just fine. I don't know if there's enough meat to do any port matching because I never got that far (found a set, but didn't buy them). The 340 manifolds are currently being repoped if you've got enough money.
that doesn't surprise me. do you think there would be any way to match the ports on the manifold to the head by doing a gasket match to the 360 exhaust gasket and then removing the material to match them. or will they be too far off?
That looks like a 273 64-66 A body manifold. 67 and up is different. The 64-66 are a narrower body. Yes, it can be used on 360 heads, but check for ports in the head. They will need to be blocked off.
yeah it is the manifold from a 66 valliant. i took that picture from shadow mt customs blog site about stuffing a 273 into his 1950 dodge. I'm planning on doing the same swap on my 54 plymouth. those manifolds would be the easy way to go otherwise i'm going to get my buddy to help me get some fenderwell headers going. The truck that i might be buying is an 80s ramcharger if that information helps.
The 318 manifolds will bolt on. There is enough meat to port match them also. They have a much smaller internal volumn than real 340 manifolds. Also look at dakota manifolds. They flow well and tuck up tight. Especially the 1992 318 ones with the larger outlet.
that's great info. i KNOW i can find manifolds from a 90s dakota. otherwise i was gonna have to search ebay for manifolds from a 60s mopar a body and probably pay a pretty penny for em. would i be able to port match the dakota manifolds to the 360 exhaust ports too or will they bolt right on?
Yeh how many of those early A manifolds ya need? I think I have like 5 in the shed. Their is also nothing wrong with running header gaskets on them.
You might want to make sure they are 360 heads.They had better been milled a bunch or you won't have much compression ratio with the 360 heads.Like others have said they will fit.
yeah i did some research and then asked the guy about it. i think they are supposed to be milled down to where the combustion chamber is either 63cc or 73cc (i can't remember) to get the compression up. He's had it milled correctly, or so he says, when he had the engine rebuilt. from what i understand if you don't mill them then the engine will barely run b/c the compression is so low. good to know the manifolds will fit thanks fellas
I ran 360 heads on 318's for years. The lower compression worked great with 88 octane farm fuel. More power than 318 heads, just not optimum.
yeah a lot of people will put larger 360 valves in teh 318 heads from what i understand. This avoids the problem of milling the heads down. i think it's six of one and half a dozen of the other. i'm not sure though.
The 360 heads on either a 318 or a 273 will work ok as long as the 273 has the late intake with the angled intake manifold bolts. The Vallent exhaust manifolds will work out OK as long as you don't intend on doing any heavy duty racing, the the flow will probably be too restrictive for hd racing. Are not the Dakota 318 exhaust manifilds a rear exit? That could be an issue with firewall clearance, depending on your chassis set up. Gene
This shows the 72 up 340 manifold, should be same for 74-6 360 A-body. They are a little less pricey than the 70-71. These use a heat stove for the air cleaner so they look a little weird but work great. Also notice the smog holes below the manifold. I tapped the holes and installed 1/4 set screws to prevent exhaust leakage.
Sorry to dig up old stuff but maybe I can get some help.I'm using 318 manifolds on a 360 because of steering clearance issues.well I didn't know the 360 manifolds had a big piece that seals the lower holes that the 318's dont seal.what do I do?
The Jalopy Journal
