LA 340 Intake Manifold

340inabbody said
So it looks like the exhaust from the LA manifolds are compatible with the Magnum engine. So my headers should work.

What about the intake manifold (SB-LA to 360 Magnum)? If not what manifolds are there for a carburetor set up on a Magnum?

Nope. The bolt holes are different. LA angled (almost 90° to the head) and the magnums are vertical. Some new manifolds have dual bolt holes.