Fenderwell Headers
The pics that yellow68runner posted look a lot like the set I have & the cutouts are nearly identical. Mine are an old set of Cyclones (purchased in 1976) with 1 5/8" tubes. Here's a couple of pics. Sorry about the quality, they're ancient (like me). My tubes do look a bit smaller. The headers seem to sit a bit lower in the chassis than his. Might be partially due to worn out motor mounts.