The Magnum version of the Edelbrock airgap manifold has the thermostat in the correct location and correct size for factory Magnum serpentine setup and AC compressor.
The LA version of the Edelbrock airgap, and the chinese copies, have the larger LA thermostat located too far left to make the Magnum AC compressor bracket fit easily, although some got creative and made them work with modificatons.
If you know you are staying carbureted, the Edelbrock Magnum airgap is best choice.