340 exhaust manifolds
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
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
