360 sb la ?
Year make model. If you are working on a 5.9 Magnum please call it that. Yes, a 5.9 is 360, but it is not a 360. It is a Magnum 5.9.
As others said they changed the neck size at some point. What intake do you have? Someone may have swapped intake manifolds, and some aftermarket manifolds are drilled for both neck sizes
Example of an Edelbrock, drilled for both
Year make model. If you are working on a 5.9 Magnum please call it that. Yes, a 5.9 is 360, but it is not a 360. It is a Magnum 5.9.
As others said they changed the neck size at some point. What intake do you have? Someone may have swapped intake manifolds, and some aftermarket manifolds are drilled for both neck sizes
Example of an Edelbrock, drilled for both
