hi, i am trying to find a good exhaust header for my 240z, but i dont know which brand has the best header in performance and fitting. thank you all in advance.

Do a search? There are a lot of opinions on this subject. Best for performance on a stock 240Z is probably a Stahl header. MSA carries them but they are pricey. Nismo & MSA also make nice headers.

Since Last Week I Keep Hearing A Clicking Sound From The Engine Bay When I Step On The Gas. I Asked Someone Who Is A Mechanic And At First He Said It Could Be The Exhaust Header Or A Bad Spark Connection, But After A Search Through The Engine He Is 100% Sure It's The Header Because There Is A Crack On The Header Where The Bolt Is Located. I Have Never Heard A Clicking Sound Coming Out Of A Crack Header Before. Could It Be The Exhaust Header?

On 73 240z If I Want To Take The Exhaust Header Off, Do I Have To Take The Intake Monifold And The Carbs Off First? I Have Never Done This Before, What Do I Need To Know In Advance For Nothing Having Too Many Problems At The End For Removing All Of These Parts? Thanks Again