409 Exhaust Manifolds

Mark Steele

Well Known Member
A beautiful set of original 409 exhaust manifolds. They spent most of their lives on the shelf. Casting numbers are 3814682 and 3814683. I live in western NY. Open to offers.


Well Known Member
Any idea how much HP loss. I have the 425 qb block with a mild cam. I’m not looking to race the car but I sure would like to have the car at it’s full potential.

Don Jacks

Well Seasoned Member
Supporting Member 3
About 25-30 from the oem high performance 63-64 QA and QB engines,65-70 off from a decent header like a Wilson,and the headers are much cheaper than either the factory high performance manifolds or the repops.These engines need to breath for both power and torque.If you want the full potential,headers are the only way to go,period.