NOS 1963 to 1967 GM factory off road exhaust pipe / muffler #3845735 & #3845736, fits 327, 427 396 engines (original GM stickers, with some mild surface rust on the pipes) - $2,000 for the pair. NOS 1966 and 1967 GM factory side exhaust pipes/mufflers #3877215 & #3877216 for 327 engine (original GM stickers). Pick up near Philly, PA