Which set of 340 exhaust manifolds work best for the magnum swap. There appears to be several versions of these manifolds. Does the drivers side one that exits right top rear the best. A pic of what you used would help.
340 exhaust manifolds
- Thread starter ed1946
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72Dart6pack
Harder Better Faster Stronger.
What are you putting it in? A John Deere tractor? Question is too vague.
72 dart
pishta
I know I'm right....
would these work for installing 360 magnum in 72 dart, has power steering
these are off 318
pishta
I know I'm right....
ports will be too small and may not even seal with 360 gaskets. Use 318 gaskets but your leaving power on the table. Id go with Magnum logs, they are inexpensive, sized right and flow well. custom head pipes...or get them off the truck youll pull them from. Its a start.
512Stroker
We are all here because we are not all there.
I have a couple sets if you need them.
I dont know if they are the "best" but they will work and they are cheap$
sent message via conversation
Treblig
Well-Known Member
The best flowing combination would be a 70s 340 driver's manifold and a Jeep Grand Cherokee (96/97/98) passenger's side manifold. This would give you the best flow for the lowest price. You can find a Cherokee manifold here:
Car-Part.com--Used Auto Parts Market
You can have it list manifolds by price or distance.
Car-Part.com--Used Auto Parts Market
You can have it list manifolds by price or distance.
Thanks for all the help. Have bought a set off 512Stroker, on to the next hunt.
received today, look good, thanks elmer
DionR
Well-Known Member
Be aware that the 340 manifold port can be too large for the Magnum head. I have the MP R/T heads on my motor with 340 manifold both sides and I have to run an adapter plate between them to have a chance for them to seal.
The reality is, I think the Magnum uses a 318 exhaust port size, or at the least is smaller then the 340/360 ports. They don't drop down on the bottom as much.
Part of the issue is whether the Magnum head has extra material below the port. Mine doesn't and the manifold opening starts almost exactly where the material on the head ends. This leaves a small window at the bottom of the port where there is no crush on the gasket.
5.9magnum questions
The reality is, I think the Magnum uses a 318 exhaust port size, or at the least is smaller then the 340/360 ports. They don't drop down on the bottom as much.
Part of the issue is whether the Magnum head has extra material below the port. Mine doesn't and the manifold opening starts almost exactly where the material on the head ends. This leaves a small window at the bottom of the port where there is no crush on the gasket.
5.9magnum questions
Treblig
Well-Known Member
I have found that the magnum port matches the 340 exhaust manifold. The 96/97/98 318/360 Jeep Grand Cherokee exhaust ports are the same as the 340 exhaust ports.....no difference. The only smaller exhaust ports are the early 273/318 engine heads. treblig
I will ck when I get ready to work on motor
bobscuda67
Well-Known Member
The Magnum port is shorter in height than the 340 LA port and will leak out of the bottom. I had to make adapters to go from Magnum heads to the 340 exhaust manifolds.
Check out post 14.
Check out post 14.
So what do adapters look like? I really don't have any equipment to make adapters. How about putting the 2 different gaskets, 340 and magnum, together behind 340 manifolds.
Next time please start a wanted thread. Thanks
DionR
Well-Known Member
My adapters are just 14 or 16 gauge plates with the inside shape matching the inside of the Magnum exhaust gasket, and the outside matching the 340 manifold. Then I sandwiched them between a Magnum gasket on the head side and a 340 gasket on the other side.
In my case, they have been a little problematic, too. I expect that at some point I will just spring for a set of Doug's headers and get rid of them. I had to re-gasket them once and the second time around they didn't seal well. Could have been something I did wrong, or could be they don't want to seal more than once.
I have pictures of them installed, but I don't think I have any after I got them cut on a plasma table here at work.
Here is a screenshot of the AutoCAD file I used to get them cut. Started with a scan of both gaskets and traced what I needed and merged them together.
In my case, they have been a little problematic, too. I expect that at some point I will just spring for a set of Doug's headers and get rid of them. I had to re-gasket them once and the second time around they didn't seal well. Could have been something I did wrong, or could be they don't want to seal more than once.
I have pictures of them installed, but I don't think I have any after I got them cut on a plasma table here at work.
Here is a screenshot of the AutoCAD file I used to get them cut. Started with a scan of both gaskets and traced what I needed and merged them together.
ok, thanks
bobscuda67
Well-Known Member
That's what mine ended up looking like. Except I made mine by hand out of 16 gauge flat stock.
They have been on the engine for 9 years and no leaks.
They have been on the engine for 9 years and no leaks.
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