Hello, I am looking to replace my factory exhaust manifolds with smog air pump lines to a none emissions exhaust manifold. The lines are rusty and keeping leaking exhaust and its getting old with the ticking it makes. Looking for a permanent solution to the issue.. Will any Olds 350, 403 manifolds from the 1970s fit the 1984 307 without changing the factory exhaust? I am guessing the manifolds are the same,(correct me if I'm wrong), but will the factory exhaust pipes bolt up to it? Cant find any info about it. Thank you in advance for any info on this.

 

The mid 70's and up are the same outlet angle with any Olds V8 that had a factory catalytic converter. The lines go in the head and goes to the cat, does it not, it has been over 20 years since I saw one of these in the wild. You will be lacking the O2 sensor port as well.