Flowmaster's manifold downpipe kits are designed for the person who wants to use a Header-back exhaust system while using the factory exhaust manifolds.
They are designed to fit the following cars with Big Block Chevy engines:
'65-'74 GM A-body
'67-'74 GM F-Body
'68-'74 GM X-Body
'68-'70 GM B-Body
Utilizing mandrel bent 409S stainless steel tubing and high quality flange gaskets, Flowmaster's manifold downpipe kits are designed for the perfect leak free fit. Mandrel bent 16 gauge stainless steel tubing.